This site is mobile accessible. Press the "Tap Here" button to use a larger font-size.

Smartphone icons created by Freepik - Flaticon

14.4 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 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 1: JS HTML DOM - Finding HTML Element by Id

const element = document.getElementById("intro");

If the element is found, the method will return the element as an object (in element).
If the element is not found, element will contain null.

Finding HTML Elements by Tag Name

This example finds all <p> elements:

Example 2: JS HTML DOM - Finding HTML Elements by Tag Name part 1

const element = document.getElementsByTagName("p");

This example finds the element with id="main", and then finds all <p> elements inside "main":

Example 3: JS HTML DOM - Finding HTML Elements by Tag Name part 2

const x = document.getElementById("main");
const y = x.getElementsByTagName("p");

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".

Example 4: JS HTML DOM - Finding HTML Elements by Class Name

const x = document.getElementsByClassName("intro");

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 5: JS HTML DOM - Finding HTML Elements by CSS Selectors

const x = document.querySelectorAll("p.intro");

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 6: JS HTML DOM - Finding HTML Elements by HTML document.forms

const x = document.forms["frm1"];
let text = "";
for (let 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:

JavaScript Fundamentals course home
Module 14. JS HTML DOM

Navigate this module

Eventually the navigation links, above, will be replaced by these << (previous) and >> (next) buttons below.

JavaScript icons used in the buttons provided by ICONS8.COM. Smartphone icons created by Freepik - Flaticon

Example files created in this module:
HTML DOM Methods JS HTML DOM - Finding HTML Element by Id JS HTML DOM - Finding HTML Elements by Tag Name part 1 JS HTML DOM - Finding HTML Elements by Tag Name part 2 JS HTML DOM - Finding HTML Elements by Class Name JS HTML DOM - Finding HTML Elements by CSS Selectors JS HTML DOM - Finding HTML Elements by HTML document.forms JS Changing HTML Content part 1 JS Changing HTML Content part 2 JS HTML DOM - Changing the Value of an Attribute JS HTML DOM - Dynamic HTML content JS HTML DOM - document.write() JS Validation - HTML Form Example part 1 JS Validation - HTML Form Example part 2 JS HTML DOM - Changing the HTML style JS HTML DOM - Changing the HTML style Using Events My first JS animation part 1 My first JS animation part 2 JS HTML Events - The onclick Attribute part 1 JS HTML Events - The onclick Attribute part 2 JS HTML Events - The onclick Attribute part 3 JS HTML Events - The onclick Attribute part 4 JS HTML Events - The onload Attribute JS addEventListener() part 1 JS addEventListener() part 2 JS addEventListener() part 3 JS addEventListener() part 4 JS addEventListener() part 5 JS addEventListener() part 6 JS addEventListener() part 7 JS addEventListener() part 8 JS removeEventListener() JS HTML Child Nodes and Node Values part 1 JS HTML Child Nodes and Node Values part 2 JS HTML Child Nodes and Node Values part 3 JS HTMLDOM - DOM Root Nodes part 1 JS HTMLDOM - DOM Root Nodes part 2 JS HTMLDOM - The nodeName Property JS HTMLDOM - The nodeType Property JS HTML DOM - Creating New HTML Elements (Nodes) JS HTML DOM - Creating new HTML Elements - insertBefore() JS HTML DOM - Removing Existing HTML Elements JS HTML DOM - Remove Child Element JS HTML DOM - Replacing an HTML Elements JS HTML DOM Collections JS HTML DOM Collections - HTMLCollection Length par 1 JS HTML DOM Collections - HTMLCollection Length part 2 JS HTML DOM - DOM Node Lists JS HTML DOM - DOM Node List Length part 1 JS HTML DOM - DOM Node List Length part 2