php查看代码执行时间工具类

<?php
class RunTime //页面执行时间类 
{
private $starttime; //页面开始执行时间 
private $stoptime; //页面结束执行时间 
private $spendtime; //页面执行花费时间 
function getmicrotime() { //获取返回当前微秒数的浮点数 
list($usec, $sec) = explode(" ", microtime());
return ((float)$usec + (float)$sec);
}
function start() { //页面开始执行函数，返回开始页面执行的时间 


$this->starttime = $this->getmicrotime();
}
function end() {//显示页面执行的时间 


$this->stoptime = $this->getmicrotime();
$this->spendtime = $this->stoptime - $this->starttime;
//return round($this->spendtime,10); 
}
function display() {
//$this->end(); 
echo "运行时间：" . round($this->spendtime, 10) . "秒";
}
} 
//调用方法 
$timer=new Runtime(); 
$timer->start(); 
for($i=0; $i<1000000; $i++) {
$b = 2;
}
$timer->end();
$timer->display();