Question

我有这个部分工作的代码。它假设要检查数据库中的现有电子邮件地址。如果没有电子邮件，则return true;

 $(document).ready(function() {

    var email_check = 0;    

        var checking_html = '<img src="http://i.imgur.com/Y8wXAZp.gif" /> Checking...';
        var characters_error = 'Minimum amount of chars is 6';

        //when button is clicked
        $('.register').click(function(){    

            //run the character number check
            if($('#email').val().length < 1){

                $('#email_result').html(characters_error);
                return false;
            }                   
            else{           
                //else show the cheking_text and run the function to check
                $('#email_result').html(checking_html);

                alert(check_email_availability());
            }
        });


  });

//function to check email availability  
function check_email_availability(){

        //get the email
        var email = $('#email').val();

        //use ajax to run the check
        $.post("check_email.php", { email: email },
            function(result){
                email_check = 0;
                //if the result is 1
                if(result == 1){
                    //show that the email is available
                    email_check = 1;

                }else{
                 email_check = 0;
                }

        });

        if (email_check == 1){  
             return true;   
        }else{
             return false;      
        }   

}

现在，问题是如果当前状态为false，当我输入数据库中没有的电子邮件并单击按钮时，我仍然会收到false警报，并且当下次我点击按钮我得到true警报。由于某种原因，该函数首先执行底部代码（检查email_check值），然后执行该函数。这是为什么？我的代码出了什么问题？如何使其执行功能，然后检查email_check值1是否为{{1}}？

Answer 1

我会改变这一点，在你的检查功能上放一个ajax成功回调。

success: function (data, status, xhr ) {
   myFunctionShowEmailSuccess();
},
error: function (xhr, status, error) {
    myFunctionShowEmailFailure();
}

Answer 2

尝试这样做。

//function to check email availability  
function check_email_availability(){

        //get the email
        var email = $('#email').val();

        //use ajax to run the check
        $.post("check_email.php", { email: email },
            function(result){
                email_check = 0;
                //if the result is 1
                if(result == 1){
                    //show that the email is available
                    return true;
                }else{
                 return false;
                }

        });

}

JavaScript函数始终运行底部代码

2 个答案: