JavaScript DOM
The DOM (Document Object Model) is a programming interface for web pages. It represents the structure of an HTML document as objects that JavaScript can access and modify.
With the DOM, JavaScript can change HTML content, styles, and attributes dynamically.
What is the DOM?
When a web page is loaded, the browser creates a Document Object Model of the page. This model allows JavaScript to interact with all elements of the page.
- JavaScript can change HTML elements
- JavaScript can change CSS styles
- JavaScript can add or remove elements
Accessing HTML Elements
You can access HTML elements using different methods. The most common method is
getElementById().
<!DOCTYPE html>
<html>
<body>
<p id="dom1">Hello</p>
<button onclick="
document.getElementById('dom1').innerHTML = 'Hello JavaScript';
">Click Me</button>
</body>
</html>
Try this code
Changing HTML Content
JavaScript can change the content of HTML elements using the innerHTML property.
<!DOCTYPE html>
<html>
<body>
<p id="dom2">Original Text</p>
<button onclick="
document.getElementById('dom2').innerHTML = 'Updated Text';
">Change Text</button>
</body>
</html>
Try this code
Changing CSS Styles
JavaScript can also change the style of HTML elements.
<!DOCTYPE html>
<html>
<body>
<p id="dom3">Styled Text</p>
<button onclick="
document.getElementById('dom3').style.color = 'red';
">Change Color</button>
</body>
</html>
Try this code
Changing Attributes
You can change HTML attributes such as images or links using JavaScript.
<!DOCTYPE html>
<html>
<body>
<img id="domImg" src="image1.jpg" width="100">
<button onclick="
document.getElementById('domImg').src = 'image2.jpg';
">Change Image</button>
</body>
</html>
Try this code
Adding Elements
JavaScript can create new HTML elements and add them to the page.
<!DOCTYPE html>
<html>
<body>
<div id="container"></div>
<button onclick="
let p = document.createElement('p');
p.innerHTML = 'New Paragraph';
document.getElementById('container').appendChild(p);
">Add Element</button>
</body>
</html>
Try this code
Removing Elements
JavaScript can also remove elements from the page.
<!DOCTYPE html>
<html>
<body>
<p id="removeMe">Remove me</p>
<button onclick="
document.getElementById('removeMe').remove();
">Remove</button>
</body>
</html>
Try this code
Why the DOM is Important
- It connects JavaScript with HTML
- It allows dynamic changes to web pages
- It is essential for interactive websites
- It is used in modern web applications