How to Efficiently Split Multibyte Strings Using mb_ereg and mb_split: A Practical Guide

3. Using mb_split for Splitting

<span><span><span class="hljs-title function_ invoke__">mb_internal_encoding</span></span><span>(</span><span><span class="hljs-string">"UTF-8"</span></span><span>); </span><span><span class="hljs-comment">// Set internal character encoding</span></span><span>
<p></span>$pattern = "[,，]+";  // Match one or more English or Chinese commas<br>
$result = mb_split($pattern, $text);</p>
<p>print_r($result);<br>
</span>

Output:

<span><span>Array
(
    [</span><span><span class="hljs-meta">0</span></span><span>] =&gt; Apple
    [</span><span><span class="hljs-meta">1</span></span><span>] =&gt; Banana
    [</span><span><span class="hljs-meta">2</span></span><span>] =&gt; Orange
    [</span><span><span class="hljs-meta">3</span></span><span>] =&gt; Grape
    [</span><span><span class="hljs-meta">4</span></span><span>] =&gt; Watermelon
)
</span></span>

mb_split automatically recognizes Chinese commas and correctly splits the string.

4. Pre-Matching with mb_ereg

In some complex scenarios, we may want to check if a certain pattern exists in the string before splitting. This can be done using mb_ereg:

<span><span><span class="hljs-keyword">if</span></span><span> (</span><span><span class="hljs-title function_ invoke__">mb_ereg</span></span><span>(</span><span><span class="hljs-string">"[,，]"</span></span><span>, </span><span><span class="hljs-variable">$text</span></span><span>)) {
    </span><span><span class="hljs-variable">$result</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mb_split</span></span><span>(</span><span><span class="hljs-string">"[,，]+"</span></span><span>, </span><span><span class="hljs-variable">$text</span></span><span>);
} </span><span><span class="hljs-keyword">else</span></span><span> {
    </span><span><span class="hljs-variable">$result</span></span><span> = [</span><span><span class="hljs-variable">$text</span></span><span>]; </span><span><span class="hljs-comment">// No splitting needed</span></span><span>
}
</span></span>

This approach avoids unnecessary splitting operations and improves efficiency.

5. Precautions

• Unified character encoding: Use mb_internal_encoding("UTF-8") to ensure all functions use UTF-8 encoding consistently, avoiding garbled text.

• Regex pattern writing: mbstring’s regex syntax differs slightly, so pay attention to brackets and escape characters.

• Performance considerations: For large texts, using mb_ereg to check before splitting can improve performance by reducing multiple regex matches.

6. Conclusion

By properly combining mb_ereg and mb_split, you can:

• Accurately handle multibyte string splitting

• Flexibly support multiple delimiters

• Optimize performance when pre-matching conditions apply

Mastering these techniques allows you to handle multilingual text smoothly and avoid common encoding and splitting errors.

Complete Example Code:

<span><span><span class="hljs-title function_ invoke__">mb_internal_encoding</span></span><span>(</span><span><span class="hljs-string">"UTF-8"</span></span><span>);
<p></span>$text = "Apple,Banana,Orange,Grape,Watermelon";</p>
<p>if (mb_ereg("[,，]", $text)) {<br>
$result = mb_split("[,，]+", $text);<br>
} else {<br>
$result = [$text];<br>
}</p>
<p>print_r($result);<br>
</span>

Running this will produce the correct split results.