Modern PHP relies heavily on an object oriented style for structuring code. You'll find this style in many libraries, frameworks and projects. Show What is an object?In PHP An object lets you handle complex data structures as single values. Let's take an address for example. It consists of several pieces of data:
With the simpler primitive types, we can't store an address in a meaningful way so we need a data structure to store an address in one single value to make sure, we keep track of every piece of data that belongs to it. We also need to make sure that all addresses have the same structure, so that the parts of our application that handle addresses can rely on. For example, the To ensure a certain object structure, we use "class", a kind of blueprint for an object. Classes
This is a class definition. It introduces a class called Class names are written in a style called
To make an address object from this class, we use the
Output:
The output tells us, it is an PropertiesNow, every property of our object is
Output:
To access a property of an object, PHP uses the MethodsBut setting every single property is tedious and not very easy to read. What if we could set it all at once? We'll need to add something to the class to do that.
Output:
What we added, is a method. A
function that is added to every object of our class. Inside a method, there's a special variable called The ConstructorsMaking an address object without any data in the first place doesn't really make sense. It would be useful, and simpler to use, if we could set the data right when we create the object. There's a special method that does that, it's called a "constructor".
The output will remain the same again. But this time, we didn't need to call an extra method to initialize our object. If a class has a method with the exact name VisibilityRight
now everything in our
That function would modify an address after it has been created and filled with data. That doesn't make sense, a place doesn't change its address, streets don't magically move to a different city. People can move to a new address but the address itself can't change. We need to prevent the address from being changed after it's created. That's where the
concept of "visibility" comes in. You might have wondered, what all the
Now we changed the visibility of our address' properties to
There are three levels of visibility in PHP: Making Addresses useful againNow we have a nice immutable (not changeable) We'll add a method that gives us the address data in a nicely formatted piece of text:
Now we can create an address and get the formatted text representation of it:
And the output will be:
We can make this more convenient by using another "magic method". PHP classes have a bunch of special methods that all start with This time we will make a
Now we can just use the address as if it were already a string:
This will produce the same output as before. We now have a class for address objects that bundles data (the properties) and some logic (the constructor and toString method) and is protected from outside modification. StaticWhile properties and methods usually belong to instances of classes, there are cases when a class itself
needs to hold values in properties or offer methods. Those are called
We can call the The visibility modifiers ( Static access is less common in PHP as it often introduces similar problems as global variables: a class with a static property is basically the same as a global variable and can make it very hard to keep track of where it is changed and where it is read from. How do I find the properties of an object in PHP?The get_object_vars() function is an inbuilt function in PHP that is used to get the properties of the given object.
How can we access properties and methods of a class in PHP?Once you have an object, you can use the -> notation to access methods and properties of the object: $object -> propertyname $object -> methodname ([ arg, ... ] ) Methods are functions, so they can take arguments and return a value: $clan = $rasmus->family('extended');
How can access properties and methods Explain with example in PHP?PHP OOP - Access Modifiers. public - the property or method can be accessed from everywhere. This is default.. protected - the property or method can be accessed within the class and by classes derived from that class.. private - the property or method can ONLY be accessed within the class.. What are properties in PHP code?Property is sometimes referred to as attribute or field. In PHP, a property is qualified by one of the access specifier keywords, public, private or protected. Name of property could be any valid label in PHP. Value of property can be different for each instance of class.
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