jQuery.isFunction()

jQuery.isFunction ( obj ) Returns: booleanversion added: 1.2

  • obj
    Type: PlainObject
    Object to test whether or not it is a function.

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. 

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>css 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. 

$.isFunction(function() {});