JavaScript HTML DOM Elements
This page teaches you how to find and access HTML elements in an HTML page.
Finding HTML Elements
Often, with JavaScript, you want to manipulate HTML elements.
To do so, you have to find the elements first. There are a couple of ways to do this:
- Finding HTML elements by id
- Finding HTML elements by tag name
- Finding HTML elements by class name
- Finding HTML elements by CSS selectors
- Finding HTML elements by HTML object collections
Finding HTML Element by Id
The easiest way to find an HTML element in the DOM, is by using the element id.
This example finds the element with id="intro":
If the element is found, the method will return the element as an object (in myElement).
If the element is not found, myElement will contain null.
Finding HTML Elements by Tag Name
This example finds all <p> elements:
This example finds the element with id="main", and then finds all <p> elements inside "main":
Example
var x = document.getElementById("main");
var y = x.getElementsByTagName("p");
Try it Yourself »
Finding HTML Elements by Class Name
If you want to find all HTML elements with the same class name, use
getElementsByClassName().
This example returns a list of all elements with class="intro".
 |
Finding elements by class name does not work in Internet Explorer 8 and earlier versions. |
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Finding HTML Elements by CSS Selectors
If you want to find all HTML elements that matches a specified CSS selector
(id, class names, types, attributes, values of attributes, etc), use the querySelectorAll() method.
This example returns a list of all <p> elements with class="intro".
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The querySelectorAll() method does not work in Internet Explorer 8 and earlier versions. |
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Finding HTML Elements by HTML Object Collections
This example finds the form element with id="frm1", in the forms collection, and displays all element values:
Example
var x = document.forms["frm1"];
var text = "";
var i;
for (i = 0; i < x.length; i++) {
text += x.elements[i].value +
"<br>";
}
document.getElementById("demo").innerHTML = text;
Try it Yourself »
The following HTML objects (and object collections) are also accessible:
- document.anchors
- document.body
- document.documentElement
- document.embeds
- document.forms
- document.head
- document.images
- document.links
- document.scripts
- document.title
Test Yourself with Exercises!
Exercise 1 » Exercise 2 » Exercise 3 » Exercise 4 » Exercise 5 »
