<span><span><span class="hljs-meta"><?php</span></span><span>
</span><span><span class="hljs-comment">// 这部分与文章内容无关,可以是任意 PHP 代码</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"初始化程序...\n"</span></span><span>;
</span><span><span class="hljs-variable">$start</span></span><span> = </span><span><span class="hljs-title function_ invoke__">microtime</span></span><span>(</span><span><span class="hljs-literal">true</span></span><span>);
</span><span><span class="hljs-keyword">for</span></span><span> (</span><span><span class="hljs-variable">$i</span></span><span> = </span><span><span class="hljs-number">0</span></span><span>; </span><span><span class="hljs-variable">$i</span></span><span> < </span><span><span class="hljs-number">1000</span></span><span>; </span><span><span class="hljs-variable">$i</span></span><span>++) {
</span><span><span class="hljs-variable">$a</span></span><span> = </span><span><span class="hljs-variable">$i</span></span><span> * </span><span><span class="hljs-variable">$i</span></span><span>;
}
</span><span><span class="hljs-variable">$end</span></span><span> = </span><span><span class="hljs-title function_ invoke__">microtime</span></span><span>(</span><span><span class="hljs-literal">true</span></span><span>);
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"初始化完成,用时:"</span></span><span> . (</span><span><span class="hljs-variable">$end</span></span><span> - </span><span><span class="hljs-variable">$start</span></span><span>) . </span><span><span class="hljs-string">" 秒\n"</span></span><span>;
</span><span><span class="hljs-meta">?></span></span><span>
<hr>
<h1>如何使用 </span><span><span class="hljs-title function_ invoke__">microtime</span></span><span>() 函数获取高精度时间戳?学习在 PHP 中精确记录时间的技巧</h1>
<p>在开发 PHP 应用时,有时我们需要精确地记录程序运行时间,尤其是在性能调优、日志记录或者生成唯一标识符时。PHP 提供了 <code></span><span><span class="hljs-title function_ invoke__">microtime</span></span><span>()
这样,你就可以得到带有微秒精度的执行时间,非常适合性能分析。
如果你想获取字符串形式的高精度时间:
<?php
</span><span><span class="hljs-variable">$time_str</span></span><span> = </span><span><span class="hljs-title function_ invoke__">microtime</span></span><span>();
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"当前微秒时间字符串:<span class="hljs-subst">$time_str</span></span></span><span>";
?>
输出类似:
</span><span><span>0.123456</span></span><span> </span><span><span>1692871234</span></span><span>
这里,前半部分是微秒,后半部分是秒数,可以自行拆分进行处理。
利用 microtime(true),我们可以生成精确到微秒的唯一 ID:
<?php
</span><span><span class="hljs-variable">$unique_id</span></span><span> = </span><span><span class="hljs-title function_ invoke__">str_replace</span></span><span>(</span><span><span class="hljs-string">'.'</span></span><span>, </span><span><span class="hljs-string">''</span></span><span>, (</span><span><span class="hljs-keyword">string</span></span><span>)</span><span><span class="hljs-title function_ invoke__">microtime</span></span><span>(</span><span><span class="hljs-literal">true</span></span><span>));
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"高精度唯一ID:<span class="hljs-subst">$unique_id</span></span></span><span>";
?>
这种方法常用于生成日志文件名或任务标识符,避免重复。
PHP 的 microtime() 函数是获取高精度时间戳的利器。通过它,你可以:
结合浮点数或字符串形式的返回值,可以灵活地满足不同场景的需求,让你的 PHP 程序在时间控制和性能分析上更加精准。