php計算頁面運行時間類

<?php
error_reporting(E_ALL);
class RunTime{
private $startTime='';
private $endTime='';
function __construct() {
$this->startTime = $this->getMicroTimeAsFloat();
}
function getMicroTimeAsFloat(){
list($fractionalSeconds,$seconds)=explode(" ", microtime());
return ((float)$seconds + (float)$fractionalSeconds);
}
function elapsed(){
$this->endTime = $this->getMicroTimeAsFloat();
return ($this->endTime - $this->startTime);
}
}
運行方式：引入該類，在頁面頭部初始化，$rt= new Runtime(); 頁面底部顯示 echo $rt->elapsed();