How to get the class name for a HTML element in Javascript
Name of a class
The following code defines style for a paragraph under p.newclass in
the style section. Then it sets the class name for a paragraph in Javascript code. In
this way we can change or add style for a HTML element.
Example
<!DOCTYPE HTML>
<html>
<head>
<style>
p { <!--from www. j av a2 s. c om-->
border: medium double black;
}
p.newclass {
background-color: grey;
color: white;
}
</style>
</head>
<body>
<p id="textblock" class="Survey numbers">
This is a test. This is a test.
This is a test. This is a test.
This is a test. This is a test.
</p>
<button id="pressme">Press Me</button>
<script>
document.getElementById("pressme").onclick = function(e) {
document.getElementById("textblock").className += " newclass";
};
</script>
</body>
</html>