Question

function checkform(for1)
{ 
   var result=checkform1(for1);
   alert(result);
}
function checkform1(form)
{
    var valid=false;
    var val1 = document.getElementById('security_code').value;
    $.get(url, function(data) {
        if(data.toString()==val1.toString())
        {
            var elem = document.getElementById("captchaerr");
            elem.style.visibility = 'hidden';
            valid=true;
        }
        else
        {
            var elem = document.getElementById("captchaerr");
            elem.style.visibility = 'visible';
            valid=false;
        }           
    }); 
    return valid;
}

即使condtion（data.toString（）== val1.toString（））为true，

结果警告始终为false 控制如何通过这个。 thnks ..

Answer 1

默认情况下，$ .get aka Ajax.get是异步的（它在后台运行）。所以你的函数“checkform1”在Ajax请求完成之前返回并设置“valid”变量。

Answer 2

不要使用toString（）作为字符串。toString()将返回string。只需测试data == val1。

Answer 3

您正在进行异步调用，因此如果要检查结果，则必须在回调中执行此操作

 function checkform1(form)
{
    var valid=false;
    var val1 = document.getElementById('security_code').value;
    $.get(url, function(data) {
        if(data.toString()==val1.toString())
        {
        var elem = document.getElementById("captchaerr");
        elem.style.visibility = 'hidden';
        valid=true;
        }
        else
        {
        var elem = document.getElementById("captchaerr");
        elem.style.visibility = 'visible';
        valid=false;
        }      
        //here you will get the valid and 
        //not outside...outside it will be always false.
    }); 

    //This line will be executed immediately after the previous line
    // and will not wait for the call to complete, so this needs to be done 
    // in the callback. 
    return valid;

}

Answer 4

如果你的'get'ajax调用是异步调用，你可以使用回调来获得结果：

function checkform(for1)
{ 
   checkform1(for1, function(result) //provide the callback to the async function
   {
     alert(result); 
   });      
}
function checkform1(form, callback)
{
    var valid=false;
    var val1 = document.getElementById('security_code').value;
    $.get(url, function(data) 
    {
        if(data.toString()==val1.toString())
        {
            var elem = document.getElementById("captchaerr");
            elem.style.visibility = 'hidden';
            valid=true;
        }
        else
        {
            var elem = document.getElementById("captchaerr");
            elem.style.visibility = 'visible';
            valid=false;
        }           
        if(callback)
            callback(valid);// call the callback INSIDE of the complete callback of the 'get' jquery function
    }); 

}

Answer 5

就在条件将警报放在两个值alert（val1 +'---'+ data）之前，看它是否完全相同。

在比较前修剪它们，以防万一它有一些填充。

即使条件为真，函数返回false也是如此？

5 个答案: