jQuery 检查返回未定义 [英] jQuery check returns undefined

问题描述

我在 jQuery 方面的经验有限，我四处寻找答案，但似乎找不到.

My experience in jQuery is limited and I've searched around for an answer but can't seem to find it.

此函数根据 get 返回 false 或 true.现在我的问题是，如果我获得数据，可用性"函数不会返回 false 或 true.

This function returns a false or true based on a get. Now my problem is that the function 'Availability' doesn't return a false nor true if I get my data.

这是代码.

function Availability(){
    var email = jQuery('#emailRegister').val();
      jQuery.get("test.php", {email: email})
        .done(function(data) {
          if(data == 'true'){
            jQuery(".warningEmailDuplicate").hide();
            return true;
          }else if(data == 'false'){
            jQuery(".warningEmailDuplicate").show();
            return false;
        }
    });
}

推荐答案

jQuery.get 创建一个 AJAX 请求.这些是异步的.您不能将 AJAX 回调中的值return 给调用函数.在 HTTP 请求完成之前，该函数将退出，不返回任何内容.

jQuery.get creates an AJAX request. These are asynchronous. You cannot return a value from the AJAX callback to the calling function. The function will have exited, returning nothing, before the HTTP request completes.

您需要重写代码才能使用回调:

You need to rewrite your code to use callbacks:

function Availability(){
    var email = jQuery('#emailRegister').val();
      jQuery.get("test.php", {email: email})
        .done(function(data) {
          if(data == 'true'){
            jQuery(".warningEmailDuplicate").hide();
            AvailabilityResult(true);
          }else if(data == 'false'){
            jQuery(".warningEmailDuplicate").show();
            AvailabilityResult(false);
        }
    });
}

function AvailabilityResult(available) {
    // *available* will be true or false
    // do with this value what you wanted to do with the return value from Availability
}

这篇关于jQuery 检查返回未定义的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！