Question

As the best option for getting return data from an ajax call was to use a function. In my case below, I called the function returnData() but how do I get this outside this returnData() function?

           var testFile = $("#selection").val(),
           testData = getTestData(testFile); 

           function getTestData(testF) {
           $.getJSON("test.php", {
           fileTest: testF
           }, function (data) {
              $.each(data, function (index, value) {
                if (value != "") {} else {
                 testArray[index] = value;
               }
           });
       });
         returnData(testArray);
      } ​ 

Answer 1

var result = null;

result = getTestData();

function getTestData(){
    return returnData(testArray);
}

alert(result);

By the way, where was testArray defined in the first place? It seems from your code it was already defined outside of getTestData().

Also, the code behind callback will probably be executed before the AJAX function returns:

var noodleIsCooked = false;

$.post("cook.php", {"Start cooking"}, function(){
    noodleIsCooked = true;
});

eatNoodle();

function eatNoodle(){
    if(!noodleIsCooked){
        alert("Yike I can't eat this!");
    }
}

The above code will almost always fire the alert.

However, to eat cooked noodle, you need to put the eatNoodle() within the callback like this:

$.post("cook.php", {"Start cooking"}, function(){
        noodleIsCooked = true;
        eatNoodle();
    });