JavaScript | RegExp w Metacharacter

JavaScript | RegExp \w Metacharacter

Last Updated : 22 Apr, 2019

The RegExp \w Metacharacter in JavaScript is used to find the word character i.e. characters from a to z, A to Z, 0 to 9. It is same as [a-zA-Z_0-9].

Syntax:

/\w/

new RegExp("\\w")

Syntax with modifiers:

/\w/g

new RegExp("\\w", "g")

Example 1: This example searches the lowercase characters, uppercase characters and underscore.

<!DOCTYPE html>
<html>
  
<head>
    <title>
        JavaScript RegExp \w Metacharacter
    </title>
</head>
  
<body style="text-align:center">
      
    <h1 style="color:green">
        GeeksforGeeks
    </h1>
      
    <h2>RegExp \w Metacharacter</h2>
      
    <p>Input String: GeeksforGeeks@_123_$</p>
      
    <button onclick="geek()">
        Click it!
    </button>
      
    <p id="app"></p>
      
    <script>
        function geek() {
            var str1 = "GeeksforGeeks@_123_$";
            var regex4 = /\w/g;
            var match4 = str1.match(regex4);
  
            document.getElementById("app").innerHTML = 
                        "Found " + match4.length
                        + " matches: " + match4;
        }
    </script>
</body>
  
</html>                    

Output:
Before Clicking the button:
backw
After Clicking the button:
backw

Example 2: This example searches the lowercase characters, uppercase characters and underscores and replaces them with hash(#).

<!DOCTYPE html>
<html>
  
<head>
    <title>
        JavaScript RegExp \w Metacharacter
    </title>
</head>
  
<body style="text-align:center">
      
    <h1 style="color:green">
        GeeksforGeeks
    </h1>
      
    <h2>RegExp \w Metacharacter</h2>
      
    <p>Input String: 128@$%</p>
      
    <button onclick="geek()">
        Click it!
    </button>
      
    <p id="app"></p>
      
    <script>
        function geek() {
            var str1 = "128@$%";         
            var replacement = "#";
            var regex4 = new RegExp("\\w", "g");
            var match4 = str1.replace(regex4, replacement);
  
            document.getElementById("app").innerHTML =
                    "Found " + match4.length
                    + " matches: " + match4;
        }
    </script>
</body>
  
</html>                    