JavaScript - DOM Navigation & Collections

Overview

Estimated time: 15–20 minutes

Learn how to navigate the DOM tree and work with collections of elements using JavaScript.

Learning Objectives

• Navigate parent, child, and sibling elements.
• Work with NodeList and HTMLCollection.

Prerequisites

• JavaScript - Changing HTML & CSS

Navigating the DOM

el.parentNode;
el.firstChild;
el.lastChild;
el.nextSibling;

Collections

const items = document.getElementsByClassName('item');
for (const item of items) {
  item.style.color = 'blue';
}

Common Pitfalls

• NodeList and HTMLCollection are array-like but not true arrays (use Array.from if needed).

Summary

DOM navigation and collections are essential for working with groups of elements and building dynamic interfaces.