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:
Example
<body>
<p id="p1">Hello World!</p>
<script>
document.getElementById("p1").innerHTML = "New text!";
</script>
</body>
</html>
Example explained:
- The HTML document above contains a
<p>element withid="p1" - We use the HTML DOM to get the element with
id="p1" - A JavaScript changes the content (
innerHTML) of that element to "New text!"
This example changes the content of an <h1> element:
Example
<html>
<body>
<h1 id="id01">Old Heading</h1>
<script>
const element = document.getElementById("id01");
element.innerHTML = "New Heading";
</script>
</body>
</html>
Example explained:
- The HTML document above contains an
<h1>element withid="id01" - We use the HTML DOM to get the element with
id="id01" - A JavaScript changes the content (
innerHTML) of that element 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:
Example
<html>
<body>
<img id="myImage" src="smiley.gif">
<script>
document.getElementById("myImage").src = "landscape.jpg";
</script>
</body>
</html>
Example explained:
- The HTML document above contains an
<img>element withid="myImage" - We use the HTML DOM to get the element with
id="myImage" - A JavaScript changes the
srcattribute of that element from "smiley.gif" to "landscape.jpg"
Dynamic HTML content
JavaScript can create dynamic HTML content:
Date : Mon Jun 14 2021 13:10:07 GMT+0530 (India Standard Time)
Example
<html>
<body>
<script>
document.getElementById("demo").innerHTML = "Date : " + Date(); </script>
</body>
</html>
document.write()
In JavaScript, document.write() can be used to write directly to the HTML output stream:
Example
<html>
<body>
<p>Bla bla bla</p>
<script>
document.write(Date());
</script>
<p>Bla bla bla</p>
</body>
</html>
Never use document.write() after the document is loaded. It will overwrite the document.
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