jQuery Deferred Methods
About This Index
This page is the jQuery Deferred index for the tutorial track. Each row links to a full guide with syntax, examples, and FAQs.
Learn the jQuery overview on /jquery. Use this page when you need a Deferred API such as $.Deferred(), deferred.done(), or deferred.then().
Start with $.Deferred(), then done(), fail(), and promise()—learn then() and resolve()/reject() next.
How to Call a Deferred Method
Create a Deferred, attach handlers, settle it, and share a read-only promise:
var dfd = $.Deferred();
dfd.done(function (value) {
console.log("ok:", value);
}).fail(function (err) {
console.error("fail:", err);
}).always(function () {
console.log("cleanup");
});
dfd.resolve("ready"); // or dfd.reject("oops")
dfd.state(); // "resolved"
var p = dfd.promise(); // read-only for callers
$.ajax("/api/data").then(function (data) {
return data.items;
});jQuery Deferred Methods Table
All Deferred method guides in this jQuery tutorial series (18 tutorials).
Getting Started
4 methodsCreate Deferreds and attach the core success/failure listeners.
| Method | Description | Tutorial |
|---|---|---|
$.Deferred() | Create a Deferred for custom async workflows — register handlers, then resolve or reject. | Try it |
deferred.done() | Run a callback when the Deferred resolves successfully. | Try it |
deferred.fail() | Run a callback when the Deferred is rejected. | Try it |
deferred.promise() | Return a read-only promise so callers cannot resolve or reject. | Try it |
Handlers & Chaining
5 methodsRegister callbacks, chain transforms, and handle errors in pipelines.
| Method | Description | Tutorial |
|---|---|---|
deferred.always() | Run a callback after resolve or reject — ideal for cleanup. | Try it |
deferred.catch() | Handle rejection at the end of a promise chain (like Promise.catch). | Try it |
deferred.then() | Chain success, failure, and progress handlers — return values flow to the next step. | Try it |
deferred.pipe() | Legacy filter/chain API — deprecated in jQuery 3+; use then() instead. | Try it |
deferred.progress() | Listen for interim progress updates from notify() or notifyWith(). | Try it |
Progress
2 methodsReport interim status before final resolve or reject.
| Method | Description | Tutorial |
|---|---|---|
deferred.notify() | Send a progress update while the Deferred is still pending. | Try it |
deferred.notifyWith() | Send progress with a custom this context and argument array. | Try it |
State & Settlement
7 methodsResolve, reject, inspect status, and bind context with With-methods.
| Method | Description | Tutorial |
|---|---|---|
deferred.resolve() | Settle as successful and pass results to done() handlers. | Try it |
deferred.resolveWith() | Resolve with a custom this context and arguments in an array. | Try it |
deferred.reject() | Settle as failed and pass reasons to fail() handlers. | Try it |
deferred.rejectWith() | Reject with a custom this context and arguments in an array. | Try it |
deferred.state() | Return "pending", "resolved", or "rejected" — preferred status check in jQuery 3+. | Try it |
deferred.isResolved() | Return true if resolved — deprecated; prefer state(). | Try it |
deferred.isRejected() | Return true if rejected — deprecated; prefer state(). | Try it |
Frequently Asked Questions
Start with $.Deferred()
Open the factory guide—syntax, examples, and FAQs.
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