jQuery.isFunction( value )Returns: booleanversion deprecated: 3.3
Description: Determines if its argument is callable as a function.
-
version added: 1.2jQuery.isFunction( value )
- valueType: AnythingThe value to be tested.
-
As of jQuery 3.3, jQuery.isFunction() has been deprecated. In most cases, its use can be replaced by typeof x === "function".
Note: As of jQuery 1.3, functions provided by the browser like alert() and DOM element methods like getAttribute() are not guaranteed to be detected as functions in browsers such as Internet Explorer.
Examples:
Test a few parameter examples.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>jQuery.isFunction demo</title>
<style>
div {
color: blue;
margin: 2px;
font-size: 14px;
}
span {
color: red;
}
</style>
<script src="https://code.jquery.com/jquery-3.5.0.js"></script>
</head>
<body>
<div>jQuery.isFunction( objs[ 0 ] ) = <span></span></div>
<div>jQuery.isFunction( objs[ 1 ] ) = <span></span></div>
<div>jQuery.isFunction( objs[ 2 ] ) = <span></span></div>
<div>jQuery.isFunction( objs[ 3 ] ) = <span></span></div>
<div>jQuery.isFunction( objs[ 4 ] ) = <span></span></div>
<script>
function stub() {}
var objs = [
function() {},
{ x:15, y:20 },
null,
stub,
"function"
];
jQuery.each( objs, function( i ) {
var isFunc = jQuery.isFunction( objs[ i ]);
$( "span" ).eq( i ).text( isFunc );
});
</script>
</body>
</html> Demo:
Finds out if the parameter is a function.
$.isFunction(function() {}); Result:
true