Cara menggunakan splice multidimensional array javascript

Multidimensional arrays are not directly provided in JavaScript. If we want to use anything which acts as a multidimensional array then we need to create a multidimensional array by using another one-dimensional array. So multidimensional arrays in JavaScript is known as arrays inside another array. We need to put some arrays inside an array, then the total thing is working like a multidimensional array. The array, in which the other arrays are going to insert, that array is use as the multidimensional array in our code. To define a multidimensional array its exactly the same as defining a normal one-dimensional array. 

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    One-Dimensional array:

    var arr = []; // Empty 1D array
    var arr1 = ["A", "B", "C", "D"] // 1D array contains some alphabets
    var arr1 = [1, 2, 3, 4, 5] // 1D array contains some digits

    Multidimensional-Dimensional array:

    Method 1:

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 

    Here arr1, arr2, …arr5 are some 1D arrays that are inside salary array.

    Method 2:

    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];

    Here, salary array works like a multidimensional array. This notations are known as array literals.

    Accessing the element of salary array:

    • To access the array element we need a simple index-based notation
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    • For many iteration, we need to use loop to access the elements,
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }

    Adding elements in Multidimensional Array: Adding elements in multi-dimensional arrays can be achieved in two ways in inner array or outer array. The inner array can be done in two different ways.

    • Adding elements to inner array:
      • We can use simple square bracket notation to add elements in multidimensional array.
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    • We can use push() method to add elements in the array.
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    • Adding elements to outer array: It is much similar to previous methods.
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array

    Removing elements in Multidimensional Array: We can use pop() methods to remove elements from inner-arrays, and also use pop() method for removing a entire inner array.

    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();

    Example 1:

    javascript




    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    0
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    1
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    2

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    5
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    0
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    1
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    2

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    5
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    0
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    2

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    2
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    3
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    7

    Output:

    ABC, 24, 18000
    EFG, 30, 30000
    IJK, 28, 41000
    EFG, 31, 28000
    EFG, 29, 35000

    Example 2:

    javascript




    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    0

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    2

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    1
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    9

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    1
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    1

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    2
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    3
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    7

    Output:

    ABC, 24, 18000
    EFG, 30, 30000
    IJK, 28, 41000
    EFG, 31, 28000
    EFG, 29, 35000

    Example 3: 

    javascript




    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    00

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    1
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    9

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    1
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    1

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    24
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    25
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    3
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    30
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    31
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    3
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    7

    Output:

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    1

    Example 4: 

    javascript




    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    0

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    39

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    41

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    1
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    9

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    1
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    1

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    65

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    68
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    2
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    3
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    83

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    85
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    86
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    87

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    91
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    2
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    3
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    07

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    09
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    10
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    13
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    14
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    15
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    16
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    20

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    2
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    3
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    7

    Output:

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    2

    Example 5: 

    javascript




    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    0

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    37

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    1
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    9

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    1
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    1

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    65

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    64
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    73

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    79
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    83

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    85
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    86
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    87

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    73

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    7

    Output:

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    3

    Example 6:

    javascript




    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    0

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    03

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    05

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    5

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    1
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    9

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    1
    salary.push(["MNO", 29, 33300]);
    // This row added after the last row in the "salary" array
    7

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3].push("India", "Mumbai");
    
    // It add "India" at the 4th index and "Mumbai" at
    // 5th index of 4th sub-array
    // If we print the entire 4th sub-array,
    // document.write(salary[3]);
    // The output will be :  ["EFG", 31, 28000, "India", "Mumbai"]
    // Indexing starts from 0
    7
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    1

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // Remove last element from 4th sub-array
    // That is 28000 indexing starts from 0
    salary[3].pop(); 
    
    // Removes last sub-array
    // That is "["EFG", 31, 28000]"
    salary.pop();
    3

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    65

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    64
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    73

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    47

    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    48
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    09
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    50
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    54

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    56

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    2
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    65
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    23
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    72
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    4

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    76

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This notation access the salary of "ABC" person which is 18000, 
    // [0] selects 1st row, and [2] selects the 3rd element
    // of that 1st row which is 18000
    salary[0][2];
    
    // Similarly, 
    salary[3][2]; // Selects 28000
    
    **This notation is used for both Method 1 and Method 2.
    78

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    63 

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    7
    // This loop is for outer array
    for (var i = 0, l1 = salary.length; i < l1; i++) {
    
        // This loop is for inner-arrays
        for (var j = 0, l2 = salary[i].length; j < l2; j++) {
    
            // Accessing each elements of inner-array
            documents.write( salary[i][j] ); 
        }
    }
    8
    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    9
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    0

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    1
    var salary = [
       ["ABC", 24, 18000],
       ["EFG", 30, 30000],
       ["IJK", 28, 41000],
       ["EFG", 31, 28000],
    ];
    73

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    6
    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    6

    salary[3][3] = "India";
    
    // It adds "India" at the 4th index of 4th sub-array,
    // If we print the entire 4th sub-array, document.write(salary[3]);
    // the output will be :  ["EFG", 31, 28000, "India"]
    // indexing starts from 0
    7

    Output:

    1st, need to define some 1D array
    var arr1 = ["ABC", 24, 18000];
    var arr2 = ["EFG", 30, 30000];
    var arr3 = ["IJK", 28, 41000];
    var arr4 = ["EFG", 31, 28000];
    var arr5 = ["EFG", 29, 35000];
    // "salary" defines like a 1D array but it already contains some 1D array
    var salary = [arr1, arr2, arr3, arr4, arr5]; 
    4

    JavaScript is best known for web page development but it is also used in a variety of non-browser environments. You can learn JavaScript from the ground up by following this JavaScript Tutorial and JavaScript Examples.