preg_match_all和preg_match的區別是什麼？各自適用場景有哪些？

gitbox 2025-09-26

<span><span><span class="hljs-meta"><?php</span></span><span>
</span><span><span class="hljs-comment">// 這裡可以是一些與文章內容無關的PHP代碼示例</span></span><span>
</span><span><span class="hljs-function"><span class="hljs-keyword">function</span></span></span><span> </span><span><span class="hljs-title">helloWorld</span></span><span>(</span><span><span class="hljs-params"></span></span><span>) {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"Hello, world!"</span></span><span>;
}
</span><span><span class="hljs-title function_ invoke__">helloWorld</span></span><span>();
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<hr>

<p><strong>標題：</strong>preg_match_all和preg_match的區別是什麼？各自適用場景有哪些？</p>

<p>在PHP中，正則表達式是處理字符串的重要工具，而<code>preg_match

輸出結果：

<span><span class="function_ invoke__">Array</span></span><span>
(
    [</span> <span><span>0</span></span> <span>] => apple
)
</span><p>在這個例子中， <span class="fun"><a href="/zh-tw/php/preg_match.html" target="_blank">preg_match</a></span>只匹配到第一個“apple”，後面的不會被捕獲。</p><h3> <span><span>2</span></span> <span>. preg_match_all 的特點</span><ul><li>用於搜索字符串中所有符合正則表達式的內容。</li><li>返回所有匹配的結果，通常以數組形式返回。</li><li>返回匹配到的次數，如果沒有匹配則返回<span class="fun">0</span> 。</li></ul><p><strong>示例：</strong></p><pre>
<?php
<span><span>$text</span></span> <span>=</span> <span><span>"apple banana apple"</span></span> <span>;
</span><span><span class="function_ invoke__">preg_match_all</span></span> <span>(</span> <span><span>&#39;/apple/&#39;</span></span> <span>,</span> <span><span>$text</span></span> <span>,</span> <span><span>$matches</span></span> <span>);
</span><span><span class="function_ invoke__">print_r</span></span> <span>(</span> <span><span>$matches</span></span> <span>);
?>
</span><p>導出結果：</p><pre>
<span><span class="function_ invoke__">Array</span></span><span>
(
    [</span> <span><span>0</span></span> <span>] =></span> <span><span class="function_ invoke__">Array</span></span><span>
        (
            [</span> <span><span>0</span></span> <span>] => apple
            [</span> <span><span>1</span></span> <span>] => apple
        )
)
</span><p>可以看到， <span class="fun">preg_match_all</span>捕獲了文本中所有的“apple”。</p><h3> <span><span>3</span></span> <span>. 適用場景</span><p><strong>preg_match</strong>適用於：</p><ul><li>只需要判斷某個模式是否存在。</li><li>只關心第一個匹配結果，而不需要全部匹配。</li><li>簡單驗證，例如驗證郵箱格式、手機號格式等。</li></ul><p> <strong>preg_match_all</strong>適用於：</p><ul><li>需要獲取字符串中所有匹配內容。</li><li>需要統計出現次數或者進行批量處理。</li><li>複雜文本分析，例如抓取網頁中所有鏈接或特定標籤內容。</li></ul><p>總結來說， <span class="fun"><a href="/zh-tw/php/preg_match.html" target="_blank">preg_match</a></span>更輕量、只關注第一個匹配，而<span class="fun">preg_match_all</span>更全面、獲取所有匹配。根據需求選擇合適的函數可以讓代碼更高效、清晰。</p></div></div>