Examples
Example 1
Use the id attribute to change a text with a JavaScript:
<html>
<head>
<script type="text/javascript">
function change_header()
{
document.getElementById("myHeader").innerHTML="Nice day!";
}
</script>
</head>
<body>
<h1 id="myHeader">Hello World!</h1>
<button onclick="change_header()">Change text</button>
</body>
</html>
The output of the code above will be:
<head>
<script type="text/javascript">
function change_header()
{
document.getElementById("myHeader").innerHTML="Nice day!";
}
</script>
</head>
<body>
<h1 id="myHeader">Hello World!</h1>
<button onclick="change_header()">Change text</button>
</body>
</html>
(more examples at the bottom of this page)
Definition and Usage
The id attribute specifies a unique id for an HTML element.
The id must be unique within the HTML document.
The id attribute can be used by a JavaScript (via the HTML DOM) or by CSS to make changes or style the element with the specified id.
Support
W3C: The "W3C" column indicates whether or not the attribute is defined in the W3C HTML/XHTML recommendation.
Browser Support
Syntax
<element id="value">
Attribute Values
| Value | Description |
|---|---|
| id | Specifies a unique id for an element. Naming rules:
|
Try it Yourself - Examples
Add a unique id of element HTML
How to add the id attribute to an HTML element.
Use the id attribute on CSS
How to use the id attribute in CSS.
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