JavaScript HTML DOM - Changing CSS
The HTML DOM allows JavaScript to change the style of HTML elements.
Changing HTML Style
To change the style of an HTML element, use this syntax:
document.getElementById(id).style.property = new style
The following example changes the style of a <p> element:
Example
<html>
<body>
<p id="p2">Hello World!</p>
<script>
document.getElementById("p2").style.color = "blue";
</script>
</body>
</html>
Try it Yourself »
Using Events
The HTML DOM allows you to execute code when an event occurs.
Events are generated by the browser when "things happen" to HTML elements:
An element is clicked on
The page has loaded
Input fields are changed
You will learn more about events in the next chapter of this tutorial.
This example changes the style of the HTML element with id="id1", when the
user clicks a button:
Example
<!DOCTYPE html><html><body><h1 id="id1">My Heading 1</h1>
<button type="button" onclick="document.getElementById('id1').style.color = 'red'">
Click Me!</button></body></html>
Try it Yourself »
More Examples
Visibility
How to make an element invisible. Do you want to show the element or not?
HTML DOM Style Object Reference
For all HTML DOM style properties, look at our complete
HTML DOM Style Object Reference.
Test Yourself With Exercises
Exercise:
Change the text color of the <p> element to "red".
<p id="demo"></p>
<script>
document.getElementById("demo") = "red";
</script>
Submit Answer »
Start the Exercise
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Reference: https://www.w3schools.com/js/js_htmldom_css.asp