php中的hexdec函数对大小写的十六进制字母有区别吗？它们会影响转换结果吗？

<span><span><span class="hljs-meta"><?php</span></span><span>
</span><span><span class="hljs-comment">// 前置无关内容示例</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"这是一段无关的PHP代码示例。\n"</span></span><span>;
</span><span><span class="hljs-variable">$time</span></span><span> = </span><span><span class="hljs-title function_ invoke__">date</span></span><span>(</span><span><span class="hljs-string">"Y-m-d H:i:s"</span></span><span>);
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"当前时间：<span class="hljs-subst">$time</span></span></span><span>\n";
</span><span><span class="hljs-meta">?></span></span><span>

<hr>

</span><span><span class="hljs-meta"><?php</span></span><span>
</span><span><span class="hljs-comment">// 正文开始</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"<h1>PHP中的hexdec函数对大小写的十六进制字母有区别吗？它们会影响转换结果吗？</h1>"</span></span><span>;

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"<p>在PHP中，<code>hexdec()