Question

see the example first then you can understand my question.

var x;
function checkTime() {
    $.ajax({ 
        type: 'GET', 
        url: 'http://www.example.com/time.php', 
        data: test,
        dataType:'json',
        success: function (data) {
            if (data == 0){
                x = 'true';
            } else if (data == 1){
                x = 'false';
            }
        }
    });
}

checkTime();
alert (x);

the alert will be undefined

I need to set x inside the checkTime functions and grab it outside the function

even if i do :

var x = checkTime();
alert (x);

i still get undefined

also i only need to check for true or false, maybe there is another way to do things. I also tried:

...
if (data == 0){
    return true;
} else if (data == 1){
    return false;
}
...

but i don’t know how to check for that.

basically i need to so something like :

if (x == 1){ // if(x == true)
//do something
}

any ideas?

thanks

Answer 1

This happens because the default behaviour of .ajax() is asynchronous. x will not have been set by the time your alert() fires. You either need to set the .ajax() with aync=false or pass in a callback function to call when your Ajax request has completed, e.g.

function checkTime(callback) {
    $.ajax({ 
        type: 'GET', 
        url: 'http://www.example.com/time.php', 
        data: test,
        dataType:'json',
        success: function (data) {
            var x = '';
            if (data == 0){
                x = 'true';
            } else if (data == 1){
                x = 'false';
            }
            // Call the callback function with 'x'
            callback.call(null, x);
        }
    });
}

And then use it like follows:

checkTime(function (x) {
    alert(x);
});