在javascript中从php脚本获取数据

Question

I try to receive a PHP response in my JavaScript.

My PHP looks like this:

some code

    if(...) echo "1";

    else echo "2";

JavaScript:

    function GetChoice() {
        var returned="";
        $.ajax({
            async: false,
            cache: false,
            url: "http://mydomain.com/script.php", 
            type: "POST",
            dataType:"text",
            success: function(data) { 
                returned = data;
            }
        });
        return returned;
    }

    var r = GetChoice();
    alert(r);

But GetChoice() returns nothing. What's wrong?

UPD: It works if javascript and php script are on the same server. My scripts in different domains.

Answer 1

GetChoice() will return nothing before the callback in success runs.

The callback, which is the function you define as the success paramater will not fire until the data have been requested from the server.

This is asyncronous (the A in AJAX) so the rest of the code with continue causing the GetChoice() function to return before the callback has been run