# jQuery.isFunction()

Categories: Utilities

## jQuery.isFunction( obj ) Returns: boolean

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

- #### version added: 1.2jQuery.isFunction( obj )

  objObject to test whether or not it is a 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:

#### Example: Test a few parameter examples.

    <!DOCTYPE html>
    <html>
    <head>
      <style>
      div { color:blue; margin:2px; font-size:14px; }
      span { color:red; }
      </style>
      <script src="http://code.jquery.com/jquery-1.7rc2.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(){});

#### Result:

    true