In this article, we will see how to add/update an attribute to an HTML element in JavaScript. There are two approaches to modify an attribute of an HTML element in JavaScript, these are.
- Using setAttribute() Method
- Using HTML DOM Attributes Property
It is used to add an attribute and provide it with a value to a specific element. If the attribute already exists, it just modifies or sets its value.
Syntax:
let elements = document.getElementById( "element_id" );
elements.setAttribute( "attribute", "value" );
Here we are initializing the element in JavaScript by getting its id and then using setAttribute() to modify its attribute.
Example: Below is the implementation of the above approach.
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content=
"width=device-width, initial-scale=1.0">
<script>
function modify() {
// Update style attribute of element "heading"
let heading = document.getElementById("heading");
heading.setAttribute("style", "color:green");
// Add style attribute to element "tagLine"
let tagLine = document.getElementById("tagLine");
tagLine.setAttribute("style", "color:blue");
}
</script>
</head>
<body>
<h1 id="heading">
GeeksforGeeks
</h1>
<p id="tagLine">- Society Of Geeks</p>
<button onclick="modify()">
Click to modify
</button>
</body>
</html>
|
Output:
How to add/update an attribute to an HTML element using JavaScript?
Approach 2: Using HTML DOM Attributes Property
We can modify HTML attributes by using HTML DOM Attributes property.
document.getElementById("element_id").attribute_name = attribute_value;
Example: Below is the implementation of the above approach:
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content=
"width=device-width, initial-scale=1.0">
<script>
function add() {
// Get the values of fNum and sNum using getAttribute()
const fNum = Number(document.getElementById("fNum").value);
const sNum = Number(document.getElementById("sNum").value);
const result = fNum + sNum;
// Output the result in green colour
const output = "Sum of two numbers is " + result;
document.getElementById("result").style = "color:green";
document.getElementById("result").innerHTML = output;
}
</script>
</head>
<body>
<h1 style="color:green;">
GeeksforGeeks
</h1>
<b>Enter first number :- </b>
<input type="number" id="fNum">
<br><br>
<b>Enter second number :- </b>
<input type="number" id="sNum">
<br><br>
<button onclick="add()">Add</button>
<p id="result"></p>
</body>
</html>
|
Output:
How to add/update an attribute to an HTML element using JavaScript?
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Last Updated :
25 Jul, 2023
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