为什么Google在其JSON响应中占优势？

我读了这篇文章：Why does Google prepend while(1); to their JSON responses?这对PHP脚本有什么帮助吗？我试过这个：

$time=time();
$hash=md5(mt_rand(1,200000));

$arr = array('time' => $time, 'hash' => $hash);
while(1);json_encode($arr);

Ajax返回错误提醒： Fatal error: Maximum execution time of 30 seconds exceeded in C:\xampp\htdocs\foo\1.php on line 6

Thank you Girish very much works :

1.php

<?php
$time=time();
$hash=md5(mt_rand(1,200000));

$arr = array('time' => $time, 'hash' => $hash);
echo "while(1);".json_encode($arr);

ajax -side

responseText=req.responseText.substring(9);
            var obj=JSON.parse(responseText);

            statusElem.innerHTML = obj.hash