Type:
PlainObject
or
String
A plain object or string that is sent to the server with the request.
success
A callback function that is executed if the request succeeds.
Data that is sent to the server is appended to the URL as a query string. If the value of the
data
parameter is a plain object, it is converted to a string and url-encoded before it is appended to the URL.
Most implementations will specify a success handler:
Using this structure, the example loops through the requested data, builds an unordered list, and appends it to the body.
The
success
callback is passed the returned data, which is typically a JavaScript object or array as defined by the JSON structure and parsed using the
$.parseJSON()
method. It is also passed the text status of the response.
As of jQuery 1.5
, the
success
callback function receives a
"jqXHR" object
(in
jQuery 1.4
, it received the
XMLHttpRequest
object). However, since JSONP and cross-domain GET requests do not use
XHR
, in those cases the
jqXHR
and
textStatus
parameters passed to the success callback are undefined.
Important:
As of jQuery 1.4, if the JSON file contains a syntax error, the request will usually fail silently. Avoid frequent hand-editing of JSON data for this reason. JSON is a data-interchange format with syntax rules that are stricter than those of JavaScript's object literal notation. For example, all strings represented in JSON, whether they are properties or values, must be enclosed in double-quotes. For details on the JSON format, see
https://json.org/
.
JSONP
If the URL includes the string "callback=?" (or similar, as defined by the server-side API), the request is treated as JSONP instead. See the discussion of the
jsonp
data type in
$.ajax()
for more details.
The jqXHR Object
As of jQuery 1.5
, all of jQuery's Ajax methods return a superset of the
XMLHTTPRequest
object. This jQuery XHR object, or "jqXHR," returned by
$.getJSON()
implements the Promise interface, giving it all the properties, methods, and behavior of a Promise (see
Deferred object
for more information). The
jqXHR.done()
(for success),
jqXHR.fail()
(for error), and
jqXHR.always()
(for completion, whether success or error; added in jQuery 1.6) methods take a function argument that is called when the request terminates. For information about the arguments this function receives, see the
jqXHR Object
section of the
$.ajax()
documentation.
The Promise interface in jQuery 1.5 also allows jQuery's Ajax methods, including
$.getJSON()
, to chain multiple
.done()
,
.always()
, and
.fail()
callbacks on a single request, and even to assign these callbacks after the request may have completed. If the request is already complete, the callback is fired immediately.
var jqxhr = $.getJSON( "example.json", function() {
console.log( "success" );
console.log( "second success" );
console.log( "complete" );
jqxhr.always(function() {
console.log( "second complete" );
Deprecation Notice
The
jqXHR.success()
,
jqXHR.error()
, and
jqXHR.complete()
callback methods are
removed as of jQuery 3.0
. You can use
jqXHR.done()
,
jqXHR.fail()
, and
jqXHR.always()
instead.
Additional Notes:
Due to browser security restrictions, most "Ajax" requests are subject to the
same origin policy
; the request can not successfully retrieve data from a different domain, subdomain, port, or protocol.
Script and JSONP requests are not subject to the same origin policy restrictions.
Loads the four most recent pictures of Mount Rainier from the Flickr JSONP API.
<title>jQuery.getJSON demo</title>
<script src="https://code.jquery.com/jquery-3.7.0.js"></script>
var flickerAPI = "https://api.flickr.com/services/feeds/photos_public.gne?jsoncallback=?";
$.each( data.items, function( i, item ) {
$( "<img>" ).attr( "src", item.media.m ).appendTo( "#images" );
Load the JSON data from test.js, passing along additional data, and access a name from the returned JSON data.
If an error occurs, log an error message instead.
