Detecting jQuery Object

Question

I'm writing a plugin for jQuery and I want to make it so the user can pass data to the plugin in any form. I have the JSON or array problem worked out, but I'm having trouble trying to determine if the data is a jQuery object.

data = $('#list li');
console.debug( $.isPlainObject(data) );   // false
console.debug( $.isArray(data) );         // false
console.debug( data[0].tagName == "LI" ); // true, but see note below

The last method returns true, but there is no guarantee that the user is using an LI tag for their data, so I think I need something like this:

if ( $.isjQueryObject(data) ) { /* do something */ }

Does anyone know a better method?

Apparently, there is a Ben Alman plugin for that - benalman.com/projects/jquery-misc-plugins/#isjquery — Mottie
– Mottie, Commented Oct 9, 2010 at 16:25

Christian C. Salvadó · Accepted Answer · 2010-07-04 01:53:15Z

9

The jQuery object (or its alias $) is a plain constructor function, all jQuery objects inherit from the jQuery.prototype object (or its alias jQuery.fn).

You can check if an object exists in the prototype chain of other object, by using either the instanceof operator or the isPrototypeOf method, for example:

function isjQueryObject(obj) {
  return obj instanceof jQuery;
}

Or:

function isjQueryObject(obj) {
  return jQuery.fn.isPrototypeOf(obj);
}

answered Jul 4, 2010 at 1:53

Christian C. Salvadó

831k185 gold badges929 silver badges845 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Mottie Over a year ago

Just as an update, using instanceof causes a memory leak in IE (ajaxian.com/archives/working-aroung-the-instanceof-memory-leak)

Colin O'Dell · Accepted Answer · 2010-07-04 01:42:17Z

1

The jQuery object is simply a collection of elements, stored as an array, with additional functions and stuff attached. So essentially you could use the jQuery elements just like you would a regular array.

answered Jul 4, 2010 at 1:42

Colin O'Dell

8,7178 gold badges41 silver badges75 bronze badges

2 Comments

Mottie Over a year ago

Hi thanks for the response, yes I know the jQuery object is stored as an array of objects, but I'm trying to find an easy way to differentiate it from others.

Colin O'Dell Over a year ago

Ah okay, I'd recommend trying @CMS's solution then.

Ken Redler · Accepted Answer · 2010-07-04 01:55:56Z

1

How about:

var isJq = data instanceof jQuery;

answered Jul 4, 2010 at 1:55

Ken Redler

23.9k8 gold badges60 silver badges69 bronze badges

Collectives™ on Stack Overflow

Detecting jQuery Object

3 Answers 3

1 Comment

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related