JQuery when() method
Last Updated :
31 Jul, 2024
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This JQuery.when() method in JQuery gives a way to execute callback functions depending on zero or more Thenable objects, which usually are Deferred objects that represent asynchronous events.
Syntax:
jQuery.when(deferreds)- Parameters:
- deferreds: This parameter specifies zero or more Thenable objects.
Return Value: This method returns a Promise.
There are two examples discussed below:
Example: In this example, the Deferred() is used to create a new object and after that then() method is called with notify and resolve method.
<!DOCTYPE HTML>
<html>
<head>
<script src="https://code.jquery.com/jquery-3.5.0.js">
</script>
</head>
<body style="text-align:center;">
<h1 style="color:green;">
GeeksForGeeks
</h1>
<p>
JQuery.when() method
</p>
<button onclick = "Geeks();">
click here
</button>
<p id="GFG_DOWN">
</p>
<script>
var def = $.Deferred();
function Geeks() {
$.when().then(function(a) {
alert(
"when() method called this alert()." );
});
}
</script>
</body>
</html>
Before clicking on button:
After clicking on button:
Example: In this example, the Deferred() method is used and the state of Deferred object is checked.
<!DOCTYPE HTML>
<html>
<head>
<script src="https://code.jquery.com/jquery-3.5.0.js">
</script>
</head>
<body style="text-align:center;">
<h1 style="color:green;">
GeeksForGeeks
</h1>
<p>
JQuery.when() method
</p>
<button onclick = "Geeks();">
click here
</button>
<p id="GFG_DOWN">
</p>
<script>
var def = $.Deferred();
function Geeks() {
$.when(def).done(function (x) {
$('#GFG_DOWN').append(
'when() method is executed.')
});
def.resolve();
}
</script>
</body>
</html>
