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 several 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":
Example #
var myElement = document.getElementById("intro"); var x = document.getElementsByTagName("p"); 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"); var x = document.getElementsByClassName("intro"); Finding elements by class name does not work in Internet Explorer 8 and earlier versions.
Finding HTML Elements by CSS Selectors #
If you want to find all HTML elements that match 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".
Example #
var x = document.querySelectorAll("p.intro"); 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; 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
