PHP 计算页面执行时间

<?php
class runtime
{
var $StartTime = 0;
var $StopTime = 0;

function get_microtime()
{
list($usec, $sec) = explode(' ', microtime());
return ((float)$usec + (float)$sec);
}

function start()
{
$this->StartTime = $this->get_microtime();
}

function stop()
{
$this->StopTime = $this->get_microtime();
}

function spent()
{
return round(($this->StopTime - $this->StartTime) * 1000, 1);
}

}


//例子
$runtime= new runtime;
$runtime->start();

//你的代码开始

$a = 0;
for($i=0; $i<1000000; $i++)
{
$a += $i;
}

//你的代码结束

$runtime->stop();
echo "页面执行时间: ".$runtime->spent()." 毫秒";

?>