mb_ereg_match 函数常见的正则表达式写法示例和技巧

在 PHP 中， 函数用于在多字节字符串中进行正则匹配，支持 UTF-8 等多字节编码，常用于处理中文、日文等非 ASCII 字符的文本。本文将介绍一些常见的正则写法示例及实用技巧。

1. 基本用法

语法如下：

</span><span><span>bool</span></span><span> </span><span><span class="function_ invoke__">mb_ereg_match</span></span><span>(</span><span><span>string</span></span><span> </span><span><span>$pattern</span></span><span>, </span><span><span>string</span></span><span> </span><span><span>$string</span></span><span>[, </span><span><span>string</span></span><span> </span><span><span>$option</span></span><span> = </span><span><span>""</span></span><span>])

返回 true 表示匹配成功，false 表示匹配失败。

示例：

</span><span><span class="function_ invoke__">mb_regex_encoding</span></span><span>(</span><span><span>"UTF-8"</span></span><span>); </span><span><span>// 设置正则匹配的编码</span></span><span>
</span><span><span>if</span></span><span> (</span><span><span class="function_ invoke__">mb_ereg_match</span></span><span>(</span><span><span>"^[0-9]+$"</span></span><span>, </span><span><span>"12345"</span></span><span>)) {
    </span><span><span>echo</span></span><span> </span><span><span>"匹配成功"</span></span><span>;
} </span><span><span>else</span></span><span> {
    </span><span><span>echo</span></span><span> </span><span><span>"匹配失败"</span></span><span>;
}

此示例中，正则 ^[0-9]+$ 表示字符串必须全部由数字组成。

2. 匹配中文字符

中文字符可以通过 Unicode 范围来匹配：

</span><span><span class="function_ invoke__">mb_regex_encoding</span></span><span>(</span><span><span>"UTF-8"</span></span><span>);
</span><span><span>if</span></span><span> (</span><span><span class="function_ invoke__">mb_ereg_match</span></span><span>(</span><span><span>"^[\x{4e00}-\x{9fa5}]+$"</span></span><span>, </span><span><span>"测试中文"</span></span><span>)) {
    </span><span><span>echo</span></span><span> </span><span><span>"全中文匹配"</span></span><span>;
} </span><span><span>else</span></span><span> {
    </span><span><span>echo</span></span><span> </span><span><span>"匹配失败"</span></span><span>;
}

这里 [\x{4e00}-\x{9fa5}] 是常用的中文 Unicode 范围。

3. 匹配邮箱地址

邮箱匹配示例：

</span><span><span class="function_ invoke__">mb_regex_encoding</span></span><span>(</span><span><span>"UTF-8"</span></span><span>);
</span><span><span>$pattern</span></span><span> = </span><span><span>"^[a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$"</span></span><span>;
</span><span><span>if</span></span><span> (</span><span><span class="function_ invoke__">mb_ereg_match</span></span><span>(</span><span><span>$pattern</span></span><span>, </span><span><span>"[email protected]"</span></span><span>)) {
    </span><span><span>echo</span></span><span> </span><span><span>"邮箱合法"</span></span><span>;
} </span><span><span>else</span></span><span> {
    </span><span><span>echo</span></span><span> </span><span><span>"邮箱不合法"</span></span><span>;
}

4. 匹配手机号

中国大陆手机号常见写法：

</span><span><span class="function_ invoke__">mb_regex_encoding</span></span><span>(</span><span><span>"UTF-8"</span></span><span>);
</span><span><span>$pattern</span></span><span> = </span><span><span>"^1[3-9][0-9]{9}$"</span></span><span>;
</span><span><span>if</span></span><span> (</span><span><span class="function_ invoke__">mb_ereg_match</span></span><span>(</span><span><span>$pattern</span></span><span>, </span><span><span>"13800138000"</span></span><span>)) {
    </span><span><span>echo</span></span><span> </span><span><span>"手机号合法"</span></span><span>;
} </span><span><span>else</span></span><span> {
    </span><span><span>echo</span></span><span> </span><span><span>"手机号不合法"</span></span><span>;
}

5. 常用技巧

• 设置编码：在使用 mb_ereg 系列函数前必须使用 mb_regex_encoding("UTF-8") 设置字符编码，否则中文可能匹配失败。
• 锚点使用：^ 表示开头，$ 表示结尾，可以保证全字符串匹配。
• 组合匹配：可以用 | 组合多个匹配规则，例如 ^(apple|orange|banana)$。
• 注意转义：正则中的特殊字符如 .、+、* 等，需要根据上下文进行转义。
• 性能提示：mb_ereg 系列函数相较于 preg 系列稍慢，但在处理多字节字符串时更安全可靠。

总结：mb_ereg_match 是处理多字节字符串正则匹配的利器，通过合理设置编码和正则规则，可以轻松匹配数字、中文、邮箱、手机号等常见需求。掌握这些示例和技巧，可以让你的 PHP 字符串处理更加稳健。