//计算运行时间
$starttime = explode(' ',microtime());
echo microtime().PHP_EOL;

//代码.....

//程序运行时间
$endtime = explode(' ',microtime());
$thistime = $endtime[0]+$endtime[1]-($starttime[0]+$starttime[1]);
$thistime = round($thistime,3);
echo "执行耗时：".$thistime." 秒。".time().PHP_EOL;