PHP计算程序运行时间的类

class timer {
var $StartTime = 0;
var $StopTime = 0;
var $TimeSpent = 0;
function start(){
$this->StartTime = microtime();
}
function stop(){
$this->StopTime = microtime();
}
function spent() {
if ($this->TimeSpent) {
return $this->TimeSpent;
} else {
$StartMicro = substr($this->StartTime,0,10);
$StartSecond = substr($this->StartTime,11,10);
$StopMicro = substr($this->StopTime,0,10);
$StopSecond = substr($this->StopTime,11,10);
$start = doubleval($StartMicro) + $StartSecond;
$stop = doubleval($StopMicro) + $StopSecond;
$this->TimeSpent = $stop - $start;
return substr($this->TimeSpent,0,8)."秒";
}
}
}//end class timer;

$timer = new timer;
$timer->start();
$temp=0;
for($i=0;$i<10000;$i++) for($j=0;$j<$i;$j++) $temp ++;
$timer->stop();
echo "循环 $temp 次，运行时间为 ".$timer->spent();

//脚本运行时间
$start_time = array_sum(explode(" ",microtime()));
$run_time = array_sum(explode(" ",microtime())) - $start_time;
echo('<center>Script Run Time: '.$run_time.'</center>');