Cara menggunakan php regex backreference

Try it

Types

Examples

Using groups

const personList = `First_Name: John, Last_Name: Doe
First_Name: Jane, Last_Name: Smith`;

const regexpNames =  /First_Name: (\w+), Last_Name: (\w+)/mg;
for (const match of personList.matchAll(regexpNames)) {
  console.log(`Hello ${match[1]} ${match[2]}`);
}

Using named groups

const personList = `First_Name: John, Last_Name: Doe
First_Name: Jane, Last_Name: Smith`;

const regexpNames =  /First_Name: (?<firstname>\w+), Last_Name: (?<lastname>\w+)/mg;
for (const match of personList.matchAll(regexpNames)) {
  console.log(`Hello ${match.groups.firstname} ${match.groups.lastname}`);
}

Using groups and back references

const quote = `Single quote "'" and double quote '"'`;
const regexpQuotes = /(['"]).*?\1/g;
for (const match of quote.matchAll(regexpQuotes)) {
  console.log(match[0]);
}

Using groups and match indices

By providing the d flag, the indices of each capturing group is returned. This is especially useful if you are correlating each matched group with the original text — for example, to provide compiler diagnostics.

const code = `function add(x, y) {
  return x + y;
}`;
const functionRegexp =
  /(function\s+)(?<name>[$_\p{ID_Start}][$\u200c\u200d\p{ID_Continue}]*)/du;
const match = functionRegexp.exec(code);
const lines = code.split("\n");
lines.splice(
  1,
  0,
  " ".repeat(match.indices[1][1] - match.indices[1][0]) +
    "^".repeat(match.indices.groups.name[1] - match.indices.groups.name[0])
);
console.log(lines.join("\n"));
// function add(x, y) {
//          ^^^
//   return x + y;
// }

See also