php 计算脚本执行时间

<code><span>//修改php的默认时区</span>
date_default_timezone_get(<span>'PRC'</span>);

<span>//使用微妙计算php脚本执行时间</span><span>echo</span> microtime(); <span>echo</span><span>" 返回当前unix时间戳和微秒数"</span>;
<span>echo</span><span>"<br>"</span>;


<span><span>class</span><span>Timer</span>{</span><span>private</span><span>$startTime</span>;
    <span>private</span><span>$stopTime</span>;

    <span><span>function</span><span>__construct</span><span>()</span>{</span><span>$this</span>->startTime=<span>0</span>;
        <span>$this</span>->stopTime=<span>0</span>;
    }

    <span><span>function</span><span>start</span><span>()</span>{</span><span>$this</span>->startTime=microtime(<span>true</span>);
    }

    <span><span>function</span><span>stop</span><span>()</span>{</span><span>$this</span>->stopTime=microtime(<span>true</span>);

    }

    <span><span>function</span><span>spent</span><span>()</span>{</span><span>return</span> round((<span>$this</span>->stopTime - <span>$this</span>->startTime),<span>4</span>);
    }



}

<span>$timer</span>= <span>new</span> Timer();
<span>$timer</span>->start();
usleep(<span>1000</span>);
<span>$timer</span>->stop();

<span>echo</span><span>"执行该脚本用时<b>"</span>.<span>$timer</span>->spent().<span>"</b>秒<br>"</span>;</code>