jQuery.isFunction()


jQuery.isFunction( obj )Returns: boolean

Description: Determine if the argument passed is a Javascript function object.

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:

Example: Test a few parameter examples.

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<!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="//code.jquery.com/jquery-1.10.2.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:

Example: Finds out if the parameter is a function.

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$.isFunction(function() {});

Result:

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true