Document Object in JavaScript

The Document Object is one of the most fundamental concepts in JavaScript for interacting with and manipulating web pages. It represents the HTML document loaded into the browser and provides various methods and properties to dynamically alter the content, structure, and style of the page.

What is the Document Object?

The document object is a part of the Browser Object Model (BOM) and provides an interface to the HTML content of the webpage. It is the root node of the Document Object Model (DOM) hierarchy and allows developers to access, modify, and interact with the structure of a webpage.

Key Points:

Represents the entire webpage.
Allows access to elements like <div>, <p>, <a>, etc.
Enables dynamic manipulation of the content, structure, and styling.

Example:

				
					<!DOCTYPE html>
<html>
<head>
    <title>Document Object Example</title>
</head>
<body>
    <p id="demo">Hello, World!</p> <script type="litespeed/javascript">console.log(document)</script> <script data-no-optimize="1">!function(t,e){"object"==typeof exports&&"undefined"!=typeof module?module.exports=e():"function"==typeof define&&define.amd?define(e):(t="undefined"!=typeof globalThis?globalThis:t||self).LazyLoad=e()}(this,function(){"use strict";function e(){return(e=Object.assign||function(t){for(var e=1;e<arguments.length;e++){var n,a=arguments[e];for(n in a)Object.prototype.hasOwnProperty.call(a,n)&&(t[n]=a[n])}return t}).apply(this,arguments)}function i(t){return e({},it,t)}function o(t,e){var n,a="LazyLoad::Initialized",i=new t(e);try{n=new CustomEvent(a,{detail:{instance:i}})}catch(t){(n=document.createEvent("CustomEvent")).initCustomEvent(a,!1,!1,{instance:i})}window.dispatchEvent(n)}function l(t,e){return t.getAttribute(gt+e)}function c(t){return l(t,bt)}function s(t,e){return function(t,e,n){e=gt+e;null!==n?t.setAttribute(e,n):t.removeAttribute(e)}(t,bt,e)}function r(t){return s(t,null),0}function u(t){return null===c(t)}function d(t){return c(t)===vt}function f(t,e,n,a){t&&(void 0===a?void 0===n?t(e):t(e,n):t(e,n,a))}function _(t,e){nt?t.classList.add(e):t.className+=(t.className?" 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litespeed_ui_events=["mouseover","click","keydown","wheel","touchmove","touchstart"];var urlCreator=window.URL||window.webkitURL;function litespeed_load_delayed_js_force(){console.log("[LiteSpeed] Start Load JS Delayed"),litespeed_ui_events.forEach(e=>{window.removeEventListener(e,litespeed_load_delayed_js_force,{passive:!0})}),document.querySelectorAll("iframe[data-litespeed-src]").forEach(e=>{e.setAttribute("src",e.getAttribute("data-litespeed-src"))}),"loading"==document.readyState?window.addEventListener("DOMContentLoaded",litespeed_load_delayed_js):litespeed_load_delayed_js()}litespeed_ui_events.forEach(e=>{window.addEventListener(e,litespeed_load_delayed_js_force,{passive:!0})});async function litespeed_load_delayed_js(){let t=[];for(var d in document.querySelectorAll('script[type="litespeed/javascript"]').forEach(e=>{t.push(e)}),t)await new Promise(e=>litespeed_load_one(t[d],e));document.dispatchEvent(new Event("DOMContentLiteSpeedLoaded")),window.dispatchEvent(new Event("DOMContentLiteSpeedLoaded"))}function litespeed_load_one(t,e){console.log("[LiteSpeed] Load ",t);var d=document.createElement("script");d.addEventListener("load",e),d.addEventListener("error",e),t.getAttributeNames().forEach(e=>{"type"!=e&&d.setAttribute("data-src"==e?"src":e,t.getAttribute(e))});let a=!(d.type="text/javascript");!d.src&&t.textContent&&(d.src=litespeed_inline2src(t.textContent),a=!0),t.after(d),t.remove(),a&&e()}function litespeed_inline2src(t){try{var d=urlCreator.createObjectURL(new Blob([t.replace(/^(?:<!--)?(.*?)(?:-->)?$/gm,"$1")],{type:"text/javascript"}))}catch(e){d="data:text/javascript;base64,"+btoa(t.replace(/^(?:<!--)?(.*?)(?:-->)?$/gm,"$1"))}return d}</script></body>
</html>

Accessing Document Properties

The document object has several properties that provide details about the HTML document.

Common Properties:

document.title: Gets or sets the title of the document.

				
					console.log(document.title); // Outputs the title of the page
document.title = "New Title"; // Changes the title dynamically

document.URL: Returns the URL of the current document.

				
					console.log(document.URL); // Outputs the current page URL

document.body: Refers to the <body> element of the document.

				
					console.log(document.body); // Outputs the body content

document.head: Refers to the <head> element of the document.

				
					console.log(document.head); // Outputs the head content

Selecting Elements in the Document

To interact with specific elements in the DOM, we use methods provided by the document object.

Methods for Selection:

document.getElementById() Retrieves an element by its id.

				
					<p id="greeting">Hello!</p> <script type="litespeed/javascript">const element=document.getElementById("greeting");console.log(element.textContent)</script>

document.getElementsByClassName() Retrieves elements by their class name.

				
					<div class="box">Box 1</div>
<div class="box">Box 2</div> <script type="litespeed/javascript">const elements=document.getElementsByClassName("box");console.log(elements.length)</script>

document.getElementsByTagName() Retrieves elements by their tag name.

				
					<ul>
    <li>Item 1</li>
    <li>Item 2</li>
</ul> <script type="litespeed/javascript">const items=document.getElementsByTagName("li");console.log(items.length)</script>

document.querySelector() Retrieves the first element that matches a CSS selector.

				
					<p class="info">Info 1</p>
<p class="info">Info 2</p> <script type="litespeed/javascript">const element=document.querySelector(".info");console.log(element.textContent)</script>

document.querySelectorAll() Retrieves all elements that match a CSS selector.

				
					<p class="info">Info 1</p>
<p class="info">Info 2</p> <script type="litespeed/javascript">const elements=document.querySelectorAll(".info");console.log(elements.length)</script>

Event Handling with the Document Object

Events allow interaction between the user and the webpage.

Adding Event Listeners:

Inline Events:

				
					<button onclick="alert('Button Clicked!')">Click Me</button>

Using addEventListener():

				
					<button id="myButton">Click Me</button> <script type="litespeed/javascript">const button=document.getElementById("myButton");button.addEventListener("click",function(){alert("Button Clicked!")})</script>

The document object is a powerful interface in JavaScript for interacting with the DOM. From selecting and modifying elements to handling events and styles, it enables developers to create dynamic and interactive web applications. By mastering the methods and properties of the document object, you can unlock the full potential of client-side web development. Happy coding !❤️