$.ajax Async using _jquery based on jquery

(Default: TRUE) The default setting is that all requests are asynchronous requests. If you need to send a sync request, set this option to false. Note that the synchronization request will lock the browser and the user's other actions must wait for the request to complete before it can be executed.

Copy Code code as follows:

var temp;
$.ajax ({
Async:false,
Type: "POST",
Url:defaultPostData.url,
DataType: ' JSON ',
Success:function (data) {
Temp=data;
}
});
Alert (temp);

This AJAX request is a synchronous request, and alert (temp) is not executed until the return value is returned.
If Async is set to: true, the result that the AJAX request returns is not awaited, and the statement behind Ajax is executed directly.