Change HTML Attribute Value using JavaScript

In this tutorial we will see how to Change HTML Attribute Value using JavaScript. setAttribute() method is used for this purpose which adds or updates the element's attribute.

Table of Contents

HTML Code

HTML Code is given below.

<!DOCTYPE html>
<html>
<head>
    <title>Change HTML Attribute Value using JavaScript</title>
</head>
<body>
    <button id='btn' onclick="addAttribute()">Submit</button>
</body>
</html>

JavaScript Code

JavaScript Code is given below, In this code we have used setAttribute() method which is used to add or change the existing attribute value of HTML Element.

The following code is used to add the class attribute with value 'main' in button element.

<script>
function addAttribute()
{
var a =document.querySelector("button");
a.setAttribute("class", "main");
}
</script>

The following code is used to change the id attribute value from btn to 'main' in html button element.

<script>
function addAttribute()
{
var a =document.querySelector("button");
a.setAttribute("id", "main");
}
</script>

Demo

Check Demo

Video Tutorial

Watch video tutorial on How To Change HTML Attribute Value using JavaScript.