The jQuery hasClass() method checks whether the selected elements have specified class names or not.
Return Value:
TRUE: If the specified class is present in any of the selected elements.
FALSE. If the specified class is not present in any of the selected elements.
Syntax:
$(selector).hasClass(classname)
Classname:
- Classname is a compulsory parameter of the jQuery hasClass() method, as it specifies the name of the CSS class to search for.
Example1:
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("button").click(function(){
alert($("p").hasClass("yo"));
});
});
</script>
<style>
.yo {
font-size: 200%;
color: red;
}
</style>
</head>
<body>
<h1>Hello!</h1>
<p class="yo">How are you?</p>
<p>Nice to see you again.</p>
<button>Click me</button>
</body>
</html>
Example2:
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script>
$(document).ready(function() {
$(".btn").click(function(){
var className = $(this).attr("id");
$("ul li").each(function() {
if ($(this).hasClass(className)) {
$(this).fadeTo('3000', 0.0).fadeTo('5000', 1.0);
}
});
});
});
</script>
<style>
ul{
font-family: monospace;
font-size: 15px;
font-family: monospace;
font-style: normal;
font-size-adjust: none;
width:200px;
padding:0px;
}
ul li{
background-color:turquoise;
width:100px;
margin:5px;
padding:5px;
list-style-type:none;
width:200px;
}
</style>
</head>
<body>
<h1>Click the buttons and I will show the matched classes</h1>
<ul>
<li class="red">Red</li>
<li class="green">Green</li>
<li class="green red">Green Red</li>
<li class="blue">Blue</li>
</ul>
<input type="button" class="btn" value="Red Class" id="red">
<input type="button" class="btn" value="Green Class" id="green">
<input type="button" class="btn" value="Blue Class" id="blue">
</body>
</html>