This is a shorthand Ajax function, which is equivalent to:
The success
callback function is passed the returned data, which will be an XML root element or a text string depending on the MIME type of the response. It is also passed the text status of the response.
//解释一下:上面的$.post可以用$.ajax来替代。
As of jQuery 1.5, the success
callback function is also passed a"jqXHR" object (injQuery 1.4,
it was passed the XMLHttpRequest
object).
Most implementations will specify a success handler:
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$.post( "ajax/test.html", function( data ) {
$( ".result" ).html( data );
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This example fetches the requested HTML snippet and inserts it on the page.
Pages fetched with POST
are never cached, so thecache
and
ifModified
options in jQuery.ajaxSetup()
have no effect on these requests.
//解释一下:自从jQuery1.5后是用的jqXHR 对象,而以前的版本是用的XMLHttpRequest对象。通过post方法获取的数据不会缓存。
The jqXHR Object
As of jQuery 1.5, all of jQuery's Ajax methods return a superset of theXMLHTTPRequest
object. This jQuery XHR object, or "jqXHR," returned by$.get()
implements the Promise interface,
giving it all the properties, methods, and behavior of a Promise (seeDeferred object for more information). ThejqXHR.done()
(for success),
jqXHR.fail()
(for error), andjqXHR.always()
(for completion, whether success or error) methods take a function argument that is called when the request terminates. For information about the arguments this function receives, see thejqXHR
Object section of the $.ajax() documentation.
The Promise interface also allows jQuery's Ajax methods, including$.get()
, to chain multiple
.done()
, .fail()
, and.always()
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.
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var jqxhr = $.post( "example.php", function() {
alert( "second success" );
jqxhr.always(function() {
alert( "second finished" );
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//解释一下:向example.php发送请求如果成功就弹出success,如果发送两次都成功了,就弹出second success;如果失败,弹出error;如果完成,弹出finished等。这里的done就是请求成功后执行的函数,fail就是请求失败后执行的函数,always就是无论请求成功还是失败都要执行的函数。
Deprecation Notice
The jqXHR.success()
, jqXHR.error()
, andjqXHR.complete()
callback methods introduced in jQuery 1.5 are
deprecated as of jQuery 1.8. To prepare your code for their eventual removal, usejqXHR.done()
,
jqXHR.fail()
, and jqXHR.always()
instead.
//解释一下:success、error和complete方法是在jQuery1.5中出现的,现在不推荐使用,推荐用done、fail、always来代替这些函数。