A workaround for using AJAX to assign a global variable failure exception in jquery _jquery

We're using jquery ajax to extract the data from the background after we want to assign it to the global variable, but how can not be assigned, why?

The reason is actually very simple, we use the AJAX is asynchronous operation, that is, in your assignment when the data has not been extracted, you certainly do not, so as long as the change to sync operation on the line ~

Method 1: Set up synchronization to perform AJAX operations first

Set Ajax asynchronously to false in the global or a required function, which is synchronous
$.ajaxsetup ({ 
async:false});

Then do your AJAX operations
$.post (address, parameters, function (data, status) {if (status = = "Success") {//Assign to global variable}else{ 
alert ("Wrong" );}});

Method 2: Direct use of $.ajax

$.ajax ({ 
type: "Post", 
URL: Address, 
data: "parameter" + parameter value, 
async:false, 
success:function (data) {/ Assign value to global variable;};

Instance code: