JavaScript RegExp [0-9] Expression

The RegExp [0-9] Expression in JavaScript is used to search any digit which is between the brackets. The character inside the brackets can be a single digit or a span of digits. 

Syntax: 

/[0-9]/ 

or

new RegExp("[0-9]")

Syntax with modifiers:

/[0-9]/g 

or

new RegExp("[0-9]", "g")

Example 1: This example searches the digits between [0-4] in the whole string. 

html

<h1 style="color:green">
    GeeksforGeeks
</h1>

<h2>RegExp [0-9] Expression</h2>

<p>Input String: 1234567890</p>

<button onclick="geek()">
    Click it!
</button>

<p id="app"></p>

<script>
    function geek() {
        var str1 = "123456790";
        var regex4 = /[0-4]/g;
        var match4 = str1.match(regex4);

        document.getElementById("app").innerHTML =
                "Found " + match4.length
                + " matches: " + match4;
    }
</script>

Output:

RegExp [0-9] Expression

Example 2: This example searches the digits between [0-9] in the whole string and replaces the characters with hash(#). 

html

<h1 style="color:green">
    GeeksforGeeks
</h1>

<h2>RegExp [0-9] Expression</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("[0-9]", "g");
        var match4 = str1.replace(regex4, replacement);

        document.getElementById("app").innerHTML =
            " New string: " + match4;
    }
</script>

Output:

RegExp [0-9] Expression

Supported Browsers: The browsers supported by RegExp [0-9] Expression 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 Complete Reference article.

We have a Cheat Sheet on Javascript where we covered all the important topics of Javascript to check those please go through Javascript Cheat Sheet-A Basic guide to JavaScript.