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&lt;1000000; $i++)
{
$a += $i;
}
 
//你的代码结束
 
$runtime->stop();
echo "页面执行时间: ".$runtime->spent()." 毫秒";
 
?>