Question from the jQuery test

The following example illustrates in detail what thedeferred() object does.

var request1 = $.Deferred();
var request2 = $.Deferred();

request1.done(function() { document.write("success"); });
request2.fail(function() { document.write("failed !"); });

request1.resolve(); // trigger "success"
request2.reject(); //  trigger "failed !"

It is a chainable object that can register multiple callbacks in callback queues, invoke them, and relay the success or failure of synchronous and/or asynchronous function returns.

Adeferred() object resolves at runtime.