Question

Possible Duplicate:
How to check a not defined variable in javascript
Determining if a javascript object has a given property

In my beforeSend function i have this

$.myloader.show();

But some scripts dont have that element so my this line gives me error

$.myloader.show(); gives me error that $.myloader does not exists

How can i do something like

if($.myloader exists)
$.myloader.show();

Answer 1

The most generic and solid solution is :

if (typeof $.myloader != 'undefined') {

If you’re sure your variable can’t hold anything else than a function or undefined, you might use

if ($.myloader) {

But do this only when you’re sure of the possible values because this test also match false, 0 and ''.