JavaScript RegExp exec() Method

The exec() Method in JavaScript is used to test for the match in a string. If there is a match this method returns the first match else it returns NULL.

Syntax:

RegExpObject.exec(str)

Parameters:

• str: It is the string to be searched. This is a required field. 

Return value:

• This method returns an array that contains the matched text if the match is found, else it returns null.

Example 1: This example searches for the string “computer” in the original string. 

Javascript

function geek() {
    let str =
        "GeeksforGeeks is the " +
        "computer science portal for geeks.";

    let regex = new RegExp("computer",);
    // match "computer" in string.
    let rex = regex.exec(str);
    console.log(rex.length);
    console.log(rex)
}
geek()

Output

1
[
  'computer',
  index: 21,
  input: 'GeeksforGeeks is the computer science portal for geeks.',
  groups: undefined
]

Example 2: This example searches for the string “rep” in the original string.  

Javascript

function geek() {
    let str =
        "GeeksforGeeks is the" +
        " computer science " +
        "portal for geeks.";
    let regex = new RegExp("rep");

    // Match "rep" in string.
    let rex = regex.exec(str);
    console.log(rex);
}
geek()

Output

null

We have a complete list of Javascript Functions, to check those go through the Javascript Functions Complete Reference article.

Supported Browsers: The browsers supported by the JavaScript exec() Method are listed below: 

• Google Chrome
• Apple Safari
• Mozilla Firefox
• Opera
• Internet Explorer

We have a complete list of Javascript RegExp expressions, to check those please go through this JavaScript RegExp Reference article.