如何设置 ajax responseText 等于字符串？

Question

我在使用 ajax.responseText 时遇到问题，它必须等于从 php 外部文件回显传入的字符串，问题是字符串似乎不等于 ajax.responseText,

但如果 alert(ajax.responseText) 它正是字符串 "friend_request_sent"

function friendToggle(type,user,elem){
var conf = confirm("Press OK to confirm the '"+type+"' action for user <?php echo $u; ?>.");

if(conf != true){
    return false;
}   
_(elem).innerHTML = 'please wait ...';
var ajax = ajaxObj("POST", "friend_system.php");

ajax.onreadystatechange = function() {
    if(ajaxReturn(ajax) == true) {

        if(ajax.responseText=="friend_request_sent"){          
            _(elem).innerHTML = 'OK Friend Request Sent';       
        } else if(ajax.responseText == "unfriend_ok"){
            _(elem).innerHTML = '<button onclick="friendToggle(\'friend\',\'<?php echo $u; ?>\',\'friendBtn\')">Request As Friend</button>';       
        } else{        
            alert(ajax.responseText);
            _(elem).innerHTML = 'Try again later';
        }
    }
}
ajax.send("type="+type+"&user="+user);

}

现在我从 friend_system.php

获取代码

 ...{ 
 echo"friend_request_sent";
 exit();
 }

和ajax js代码

function ajaxObj( meth, url ) {
 var x = new XMLHttpRequest();
 x.open( meth, url, true );
 x.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
 return x;
}
function ajaxReturn(x){
   if(x.readyState == 4 && x.status == 200){
    return true;    
 }

} 第三个条件是它挣扎的地方，它总是去别的地方，为什么？

Answer 1

要根据任何字符串检查 ajax 响应，最好是 trim 响应文本

request.responseText.trim() === "string"

如何设置 ajax responseText 等于字符串？

How do I set ajax responseText to be equal to string?

javascript

php

ajax

responsetext