HTML DOM getElementsByClassName() Method
Example
Get all elements with the specified class name:
var x =
document.getElementsByClassName("example");
Try it Yourself »
More "Try it Yourself" examples below.
Definition and Usage
The getElementsByClassName() method returns a collection of all elements in the document with the specified class name, as an HTMLCollection object.
The HTMLCollection object represents a collection of nodes. The nodes can be accessed by index numbers. The index starts at 0.
Tip: You can use the length property of the HTMLCollection object to determine the number of elements with a specified class name, then you can loop through all elements and extract the info you want.
Browser Support
The numbers in the table specifies the first browser version that fully supports the method.
| Method | |||||
|---|---|---|---|---|---|
| getElementsByClassName() | 4.0 | 9.0 | 3.0 | 3.1 | 9.5 |
Syntax
document.getElementsByClassName(classname)
Parameter Values
| Parameter | Type | Description |
|---|---|---|
| classname | String | Required. The class name of the elements you want to get. To search for multiple class names, separate them with spaces, like "test demo". |
Technical Details
| DOM Version: | Core Level 1 Document Object |
|---|---|
| Return Value: | An HTMLCollection object, representing a collection of elements with the specified class name. The elements in the returned collection are sorted as they appear in the source code. |
More Examples
Example
Get all elements with both the "example" and "color" classes:
var x =
document.getElementsByClassName("example color");
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Example
Find out how many elements with class="example" there are in the document (using the length property of the HTMLCollection object):
var x =
document.getElementsByClassName("example").length;
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Example
Change the background color of all elements with class="example":
var x = document.getElementsByClassName("example");
var i;
for (i = 0; i < x.length; i++) {
x[i].style.backgroundColor = "red";
}
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Related Pages
CSS Tutorial: CSS Syntax
CSS Reference: CSS .class Selector
HTML DOM Reference: element.getElementsByClassName()
HTML DOM Reference: className Property
HTML DOM Reference: classList Property
HTML DOM Reference: Style Object
HTML DOM Reference: HTMLCollection Object
