相关疑难解决方法(0)

我有一个foo发出Ajax请求的函数.我怎样才能从中回复foo？

我尝试从success回调中返回值,并将响应分配给函数内部的局部变量并返回该变量,但这些方法都没有实际返回响应.

function foo() {
    var result;

    $.ajax({
        url: '...',
        success: function(response) {
            result = response;
            // return response; // <- I tried that one as well
        }
    });

    return result;
}

var result = foo(); // It always ends up being `undefined`.

有人可以告诉我如何返回status函数返回值的值.

function checkUser() {
    var request;
    var status = false;

    //create xmlhttprequest object here [called request]

    var stu_id = document.getElementById("stu_id").value;
    var dName = document.getElementById("dName").value;
    var fileName = "check_user.php?dName=" + dName + "&stu_id=" + stu_id;
    request.open("GET", fileName, true);
    request.send(null);

    request.onreadystatechange = function() {
        if (request.readyState == 4) {
            var resp = parseInt(request.responseText, 10);
            if(resp === 1) {
                alert("The display name has already been taken.");
                status = false;
            }
            else if(resp === 2) {
                alert("This student ID has already been …