Use the hasClass() method to test if an element contains a JavaScript class.
Example
You can try to run the following code to test if an element i.e. <div> here contains a class
<html>
<body>
<div id="test" class="myClass"></div>
<script>
function hasClass(element, cls) {
return (' ' + element.className + ' ').indexOf(' ' + cls + ' ') > -1;
}
var val1 = document.getElementById('test');
alert(hasClass(val1, 'myClass'));
</script>
</body>
</html>