Php Ajax表单提交表单问题。我能'；无法获得正确的值

在下面的代码中，当我在调用ajax之前发出警报时，它会按预期执行，echo会输出正确的信息；然而，当我试图通过php传递信息时，数据似乎是空的。我在php中做错了什么

Javascript：

$('#submit_fourth').click(function(){
    //send information to server   
    var email = $('input#email').val();
    var hash = $('input#username').val();
    var type = $('input#type').val();
    var finish = "email=" + email + "hash=" + hash + "type=" + type;

    alert(finish);
    $.ajax({
        cache: false,
        type: 'POST',
        url: 'process.php',
        data: finish,
        success: function(response) {
            alert('it worked!');
        }
    }); 
});

<?php
     $to      = 'blanet910@yahoo.com';
     $subject = 'Hash testing requested';
     $message = $_POST['finish'];
     $headers = 'From: webmaster@hashtester.com' . "\r\n" .
         'Reply-To: webmaster@hashtester.com' . "\r\n" .
         'X-Mailer: PHP/' . phpversion();

    mail($to, $subject, $message, $headers);
?>

PHP：

$('#submit_fourth').click(function(){
    //send information to server   
    var email = $('input#email').val();
    var hash = $('input#username').val();
    var type = $('input#type').val();
    var finish = "email=" + email + "hash=" + hash + "type=" + type;

    alert(finish);
    $.ajax({
        cache: false,
        type: 'POST',
        url: 'process.php',
        data: finish,
        success: function(response) {
            alert('it worked!');
        }
    }); 
});

<?php
     $to      = 'blanet910@yahoo.com';
     $subject = 'Hash testing requested';
     $message = $_POST['finish'];
     $headers = 'From: webmaster@hashtester.com' . "\r\n" .
         'Reply-To: webmaster@hashtester.com' . "\r\n" .
         'X-Mailer: PHP/' . phpversion();

    mail($to, $subject, $message, $headers);
?>

这是错误的：

var finish = "email=" + email + "hash=" + hash + "type=" + type;

应至少：

var finish = "email=" + email + "&hash=" + hash + "&type=" + type;

但为了避免转义数据（您没有这样做…）时出现问题，最好使用：

var finish = $("form").serialize();

这是错误的：

var finish = "email=" + email + "hash=" + hash + "type=" + type;

应至少：

var finish = "email=" + email + "&hash=" + hash + "&type=" + type;

但为了避免转义数据（您没有这样做…）时出现问题，最好使用：

var finish = $("form").serialize();

---

应在普通对象中传递数据：

var email = $('input#email').val();
var hash = $('input#username').val();
var type = $('input#type').val();

$.ajax({
  cache: false,
  type: 'POST',
  url: 'process.php',
  data: {email: email, hash: hash, type: type},
  success: function(response) { alert('it worked!'); }
}); 

---

应在普通对象中传递数据：

var email = $('input#email').val();
var hash = $('input#username').val();
var type = $('input#type').val();

$.ajax({
  cache: false,
  type: 'POST',
  url: 'process.php',
  data: {email: email, hash: hash, type: type},
  success: function(response) { alert('it worked!'); }
}); 

---

您是否可以将finish作为查询字符串传递？

var\u dump（$message）var\u dump（$message）设置并粘贴结果后。它是一个对象，不是数组。它是一个对象，不是数组