怎樣利用base_convert() 和strtoupper() 函數實現十六進制的大寫字母轉換？

<span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 前置代碼示例，與文章內容無關</span></span><span>
</span><span><span class="hljs-variable">$greeting</span></span><span> = </span><span><span class="hljs-string">"Hello, world!"</span></span><span>;
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$greeting</span></span><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 class="hljs-comment">/*
文章內容開始
標題: 怎樣利用 base_convert() 和 strtoupper() 函數實現十六進制的大寫字母轉換？
*/</span>

</span><span><span class="hljs-comment">// 在 PHP 中，處理數值進制轉換時，base_convert() 是一個非常實用的函數。</span></span><span>
</span><span><span class="hljs-comment">// 它可以將數字從一個進制轉換到另一個進制。例如，將十進制數字轉換為十六進制：</span></span><span>

</span><span><span class="hljs-variable">$decimalNumber</span></span><span> = </span><span><span class="hljs-number">255</span></span><span>; </span><span><span class="hljs-comment">// 十進制數字</span></span><span>
</span><span><span class="hljs-variable">$hexNumber</span></span><span> = </span><span><span class="hljs-title function_ invoke__">base_convert</span></span><span>(</span><span><span class="hljs-variable">$decimalNumber</span></span><span>, </span><span><span class="hljs-number">10</span></span><span>, </span><span><span class="hljs-number">16</span></span><span>); </span><span><span class="hljs-comment">// 將十進制轉換為十六進制</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"十進制 <span class="hljs-subst">$decimalNumber</span></span></span><span> 轉換為十六進制: </span><span><span class="hljs-subst">$hexNumber</span></span><span>&lt;br&gt;"; </span><span><span class="hljs-comment">// 輸出 ff</span></span><span>

</span><span><span class="hljs-comment">// 注意：base_convert() 返回的十六進製字母默認是小寫的。</span></span><span>
</span><span><span class="hljs-comment">// 如果想要將十六進製字母轉換為大寫，可以結合 strtoupper() 函數：</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">"大寫十六進制: <span class="hljs-subst">$hexNumberUpper</span></span></span><span>&lt;br&gt;"; </span><span><span class="hljs-comment">// 輸出 FF</span></span><span>

</span><span><span class="hljs-comment">// 結合使用 base_convert() 和 strtoupper()，可以很方便地实现十進制到大寫十六進制的转换</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">// 测试函數</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"函數测试: "</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">// 輸出 FFF</span></span><span>

<span class="hljs-comment">/*
總結：
1. 使用 base_convert() 可以在不同進制之間轉換數字。
2. 十六進制默認小寫，如果需要大寫字母，可使用 strtoupper()。
3. 將兩者結合，可以輕鬆實現十六進制大寫字母的轉換。
*/</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">// 尾部代碼示例，與文章內容無關</span></span><span>
</span><span><span class="hljs-variable">$footerMessage</span></span><span> = </span><span><span class="hljs-string">"感謝閱讀！"</span></span><span>;
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-variable">$footerMessage</span></span><span>;
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>