使用 rtrim 函数删除字符串末尾特定字符的技巧

gitbox 2025-09-29
<span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-comment">// 这里是与文章内容无关的 PHP 代码示例</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"欢迎阅读 PHP 技巧分享！"</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">/*
文章标题: 使用 rtrim 函数删除字符串末尾特定字符的技巧
*/</span>

</span><span><span class="hljs-comment">// 在 PHP 中处理字符串时，经常会遇到需要删除字符串末尾多余字符的情况。</span></span><span>
</span><span><span class="hljs-comment">// rtrim 函数是 PHP 提供的一个非常实用的工具，可以针对字符串末尾进行精确的裁剪操作。</span></span><span>

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&lt;h1&gt;使用 rtrim 函数删除字符串末尾特定字符的技巧&lt;/h1&gt;"</span></span><span>;

</span><span><span class="hljs-comment">// rtrim 基本用法</span></span><span>
<span class="hljs-comment">/*
语法:
string rtrim(string $str [, string $character_mask])
参数说明:
- $str: 要处理的字符串
- $character_mask: 指定要删除的字符集合，默认删除空白字符（空格、制表符、换行等）
返回值:
- 返回删除指定字符后的字符串
*/</span>

</span><span><span class="hljs-comment">// 示例 1: 删除末尾空白字符</span></span><span>
</span><span><span class="hljs-variable">$text1</span></span><span> = </span><span><span class="hljs-string">"Hello World!    "</span></span><span>;
</span><span><span class="hljs-variable">$clean1</span></span><span> = </span><span><span class="hljs-title function_ invoke__">rtrim</span></span><span>(</span><span><span class="hljs-variable">$text1</span></span><span>);
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&lt;p&gt;原字符串: '<span class="hljs-subst">{$text1}</span></span></span><span>'&lt;/p&gt;";
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&lt;p&gt;处理后: '<span class="hljs-subst">{$clean1}</span></span></span><span>'&lt;/p&gt;";

</span><span><span class="hljs-comment">// 示例 2: 删除指定字符</span></span><span>
</span><span><span class="hljs-variable">$text2</span></span><span> = </span><span><span class="hljs-string">"filename.txtxxx"</span></span><span>;
</span><span><span class="hljs-variable">$clean2</span></span><span> = </span><span><span class="hljs-title function_ invoke__">rtrim</span></span><span>(</span><span><span class="hljs-variable">$text2</span></span><span>, </span><span><span class="hljs-string">"x"</span></span><span>); </span><span><span class="hljs-comment">// 删除末尾所有 x</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&lt;p&gt;原字符串: '<span class="hljs-subst">{$text2}</span></span></span><span>'&lt;/p&gt;";
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&lt;p&gt;处理后: '<span class="hljs-subst">{$clean2}</span></span></span><span>'&lt;/p&gt;";

</span><span><span class="hljs-comment">// 示例 3: 删除多个指定字符</span></span><span>
</span><span><span class="hljs-variable">$text3</span></span><span> = </span><span><span class="hljs-string">"abc123xyz123"</span></span><span>;
</span><span><span class="hljs-variable">$clean3</span></span><span> = </span><span><span class="hljs-title function_ invoke__">rtrim</span></span><span>(</span><span><span class="hljs-variable">$text3</span></span><span>, </span><span><span class="hljs-string">"123xyz"</span></span><span>); </span><span><span class="hljs-comment">// 删除末尾的 1、2、3、x、y、z</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&lt;p&gt;原字符串: '<span class="hljs-subst">{$text3}</span></span></span><span>'&lt;/p&gt;";
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&lt;p&gt;处理后: '<span class="hljs-subst">{$clean3}</span></span></span><span>'&lt;/p&gt;";

</span><span><span class="hljs-comment">// 小技巧:</span></span><span>
</span><span><span class="hljs-comment">// 1. rtrim 只作用于字符串末尾，如果需要删除开头的字符，可以使用 ltrim。</span></span><span>
</span><span><span class="hljs-comment">// 2. 如果想同时删除两端字符，可以使用 trim。</span></span><span>
</span><span><span class="hljs-comment">// 3. character_mask 可以组合多个字符，rtrim 会删除末尾连续出现的这些字符。</span></span><span>

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"&lt;p&gt;通过以上示例，可以看出 rtrim 在处理字符串尾部特定字符时非常灵活，尤其适合清理用户输入或文件名后缀。&lt;/p&gt;"</span></span><span>;

</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>
rtrim