如何用PHP编写代码来计算网页执行时间？

本文共计141个文字，预计阅读时间需要1分钟。

javascriptclass Timer { constructor() { this.$t_start=0; this.$t_stop=0; this.$t_elapsed=0; }

start() { this.$t_start=performance.now(); }

stop() { this.$t_stop=performance.now(); }

elapsed() { return this.$t_stop - this.$t_start; }}

<? class c_Timer { var $t_start = 0; var $t_stop = 0; var $t_elapsed = 0; function start() { $this->t_start = microtime(); } function stop() { $this->t_stop = microtime(); } function elapsed() { if ($this->t_elapsed) { return $this->t_elapsed; } else { $start_u = substr($this->t_start,0,10); $start_s = substr($this->t_start,11,10); $stop_u = substr($this->t_stop,0,10); $stop_s = substr($this->t_stop,11,10); $start_total = doubleval($start_u) + $start_s; $stop_total = doubleval($stop_u) + $stop_s; $this->t_elapsed = $stop_total - $start_total; return $this->t_elapsed; } } }; /* Here's an example usage: $timer = new c_Timer; $timer->start(); echo "<hr>"; $timer->stop(); echo $timer->elapsed(); */ ?>