The HTML DOM allows JavaScript to change the content of HTML elements.
Changing HTML Content
The easiest way to modify the content of an HTML element is by using the innerHTML property.
To change the content of an HTML element, use this syntax:
document.getElementById(id).innerHTML = new HTMLThis example changes the content of a <p> element:
<!DOCTYPE html>
<html>
<body>
<h4>JavaScript can change HTML.</h4>
<p id="example">Hello World!</p>
<script>
document.getElementById("example").innerHTML = "New text!";
</script>
<p>The paragraph above was changed by a JavaScript.</p>
</body>
</html>Output:
JavaScript can change HTML.
Hello World!
The paragraph above was changed by a JavaScript.
Example explained:
The HTML document above contains a <p> element with id=”example“. We use the HTML DOM to get the element with id=”example”. A JavaScript changes the content (innerHTML) of that element to “New text!”
This example changes the content of an <h3> element:
<!DOCTYPE html>
<html>
<body>
<h3 id="example-2">Old Heading</h3>
<script>
var element = document.getElementById("example-2");
element.innerHTML = "New Heading";
</script>
<p>JavaScript changed "Old Heading" to "New Heading".</p>
</body>
</html>
Output:
Old Heading
JavaScript changed “Old Heading” to “New Heading”.
Changing the Value of an Attribute
To change the value of an HTML attribute, use this syntax:
document.getElementById(id).attribute = new valueThis example changes the value of the src attribute of an <img> element:
<!DOCTYPE html>
<html>
<body>
<img id="image" src="https://lenadesign.org/wp-content/uploads/2021/05/bike-animation.jpg" width="320" height="240" alt="cyclist">
<script>
document.getElementById("image").src = "https://lenadesign.org/wp-content/uploads/2020/02/css-doughnut.jpg";
</script>
</body>
</html>Output:
Example explained:
The HTML document above contains an <img> element with id=”image”. We use the HTML DOM to get the element with id=”image”. A JavaScript changes the src attribute of that element from “bike-animation.jpg” to “dougnut.jpg”.
Enjoy coding!
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