怎样利用 base_convert() 和 strtoupper() 函数实现十六进制的大写字母转换？

<span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 前置代码示例，与文章内容无关</span></span><span>
</span><span><span class="hljs-variable">$greeting</span></span><span> = </span><span><span class="hljs-string">"Hello, world!"</span></span><span>;
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&lt;hr&gt;

</span><span><span class="hljs-meta">&lt;?php</span></span><span>
<span class="hljs-comment">/*
文章内容开始
标题: 怎样利用 base_convert() 和 strtoupper() 函数实现十六进制的大写字母转换？
*/</span>

</span><span><span class="hljs-comment">// 在 PHP 中，处理数值进制转换时，base_convert() 是一个非常实用的函数。</span></span><span>
</span><span><span class="hljs-comment">// 它可以将数字从一个进制转换到另一个进制。例如，将十进制数字转换为十六进制：</span></span><span>

</span><span><span class="hljs-variable">$decimalNumber</span></span><span> = </span><span><span class="hljs-number">255</span></span><span>; </span><span><span class="hljs-comment">// 十进制数字</span></span><span>
</span><span><span class="hljs-variable">$hexNumber</span></span><span> = </span><span><span class="hljs-title function_ invoke__">base_convert</span></span><span>(</span><span><span class="hljs-variable">$decimalNumber</span></span><span>, </span><span><span class="hljs-number">10</span></span><span>, </span><span><span class="hljs-number">16</span></span><span>); </span><span><span class="hljs-comment">// 将十进制转换为十六进制</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"十进制 <span class="hljs-subst">$decimalNumber</span></span></span><span> 转换为十六进制: </span><span><span class="hljs-subst">$hexNumber</span></span><span>&lt;br&gt;"; </span><span><span class="hljs-comment">// 输出 ff</span></span><span>

</span><span><span class="hljs-comment">// 注意：base_convert() 返回的十六进制字母默认是小写的。</span></span><span>
</span><span><span class="hljs-comment">// 如果想要将十六进制字母转换为大写，可以结合 strtoupper() 函数：</span></span><span>

</span><span><span class="hljs-variable">$hexNumberUpper</span></span><span> = </span><span><span class="hljs-title function_ invoke__">strtoupper</span></span><span>(</span><span><span class="hljs-variable">$hexNumber</span></span><span>);
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"大写十六进制: <span class="hljs-subst">$hexNumberUpper</span></span></span><span>&lt;br&gt;"; </span><span><span class="hljs-comment">// 输出 FF</span></span><span>

</span><span><span class="hljs-comment">// 结合使用 base_convert() 和 strtoupper()，可以很方便地实现十进制到大写十六进制的转换</span></span><span>
</span><span><span class="hljs-function"><span class="hljs-keyword">function</span></span></span><span> </span><span><span class="hljs-title">decimalToHexUpper</span></span><span>(</span><span><span class="hljs-params"><span class="hljs-variable">$number</span></span></span><span>) {
    </span><span><span class="hljs-keyword">return</span></span><span> </span><span><span class="hljs-title function_ invoke__">strtoupper</span></span><span>(</span><span><span class="hljs-title function_ invoke__">base_convert</span></span><span>(</span><span><span class="hljs-variable">$number</span></span><span>, </span><span><span class="hljs-number">10</span></span><span>, </span><span><span class="hljs-number">16</span></span><span>));
}

</span><span><span class="hljs-comment">// 测试函数</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"函数测试: "</span></span><span> . </span><span><span class="hljs-title function_ invoke__">decimalToHexUpper</span></span><span>(</span><span><span class="hljs-number">4095</span></span><span>); </span><span><span class="hljs-comment">// 输出 FFF</span></span><span>

<span class="hljs-comment">/*
总结：
1. 使用 base_convert() 可以在不同进制之间转换数字。
2. 十六进制默认小写，如果需要大写字母，可使用 strtoupper()。
3. 将两者结合，可以轻松实现十六进制大写字母的转换。
*/</span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>

&lt;hr&gt;

</span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 尾部代码示例，与文章内容无关</span></span><span>
</span><span><span class="hljs-variable">$footerMessage</span></span><span> = </span><span><span class="hljs-string">"感谢阅读！"</span></span><span>;
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$footerMessage</span></span><span>;
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>