JavaScript: Selecting and Modifying DOM Elements

JavaScript is an essential language for web development, and one of its most powerful features is the ability to manipulate the Document Object Model (DOM). This allows developers to create dynamic and interactive web pages. In this blog post, we will explore how to select and modify DOM elements using JavaScript.

Selecting DOM Elements

Selecting DOM elements is the first step in manipulating them. JavaScript provides several methods to select elements from the DOM:

getElementById: Selects an element by its ID.

const element = document.getElementById(‘myElement’);

getElementsByClassName: Selects all elements with a specific class name.

const elements = document.getElementsByClassName(‘myClass’);

getElementsByTagName: Selects all elements with a specific tag name.

const elements = document.getElementsByTagName(‘div’);

querySelector: Selects the first element that matches a CSS selector.

const element = document.querySelector(‘.myClass’);

querySelectorAll: Selects all elements that match a CSS selector.

const elements = document.querySelectorAll(‘.myClass’);

Modifying DOM Elements

Once you’ve selected an element, you can modify it in various ways:

Changing Text Content:

const element = document.getElementById(‘myElement’);

element.textContent = ‘Hello, World!’;

Changing HTML Content:

const element = document.getElementById(‘myElement’);

element.innerHTML = ‘<strong>Hello, World!</strong>’;

Changing Attributes:

const element = document.querySelector(‘img’);

element.src = ‘newImage.jpg’;

Changing Styles:

const element = document.getElementById(‘myElement’); = ‘blue’; = ’20px’;

Adding and Removing Classes:

const element = document.getElementById(‘myElement’);



Example: Creating and Modifying a Button

Let’s create a simple example where we create a button dynamically and then modify its properties:

<!DOCTYPE html>

<html lang=”en”>


    <meta charset=”UTF-8″>

    <meta name=”viewport” content=”width=device-width, initial-scale=1.0″>

    <title>DOM Manipulation Example</title>



    <div id=”container”></div>


        // Creating a new button element

        const button = document.createElement(‘button’);

        // Setting the button’s text

        button.textContent = ‘Click Me’;

        // Adding a class to the button


        // Appending the button to the container div

        const container = document.getElementById(‘container’);


        // Adding an event listener to change the button’s text when clicked

        button.addEventListener(‘click’, () => {

            button.textContent = ‘You Clicked Me!’;

   = ‘green’;





In this example:

We create a new button element using document.createElement.

We set the button’s text content and add a class to it.

We append the button to a container div.

We add an event listener to change the button’s text and background color when clicked.


Manipulating the DOM is a fundamental skill in web development. With JavaScript, you can select elements, change their content, modify their styles, and respond to user interactions, allowing you to create dynamic and interactive web pages. Practice these techniques to become proficient in DOM manipulation and enhance your web development skills.