Question

Why is this not working?

var names;

$.ajax({
     type : 'POST',
     url : postUrl+"/admin/returnUserJSON",
     success : function(data){
          names = data;
     }
});

console.log(names);

Problem: Console.log is returning undefined.

Answer 1

As $.ajax call is asynchronous, the console.log will be called before names=data line will be executed (as it’s a part of $.ajax callback function, which will be called only after the server’s response). Hence it will output undefined.

You can fix it two ways: either move your output into the callback function…

function(data){
  names = data;
  console.log(names);
}

… or make use of Promise interface:

$.ajax({
     type : 'POST',
     url : postUrl+"/admin/returnUserJSON",
     success : function(data){
          names = data;
     }
}).then(function() { console.log(names); });