技术上不可行。但是，您可以对PHP页面进行AJAX调用并获取它返回的值。

Technically not possible. However you can make an AJAX call to a PHP page and get the values returned by it.

PHP（test.php）：

PHP (test.php):

<?php
$x = 10;
$y = 20;
$val = $y / $x;

echo $val;
?>

Javascript（ jQuery ）：

Javascript (jQuery):

$(document).ready(function() {
   $.ajax({url: 'test.php',
      type: 'POST',
      success: function(data){
         //takes the value returned by test.php and
         //puts it directly into the element with 
         //id = someElement
         $('#someElement').html(data);
      }
});

至于调用 exit（）; 并制作保存JavaScript停止处理的页面，除非你在PHP中控制同一页面上的逻辑并从那里调用 exit（）; ，否则你不能这样做。

As far as calling exit(); and making the page that holds the JavaScript stop processing, you just can't unless you control the logic on that same page in PHP and call exit(); from there.