preg_match
执行正则表达式匹配
使用正则表达式对字符串中的 "w3school" 进行不区分大小写的搜索:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token variable">$str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Visit W3School"</span><span class="token punctuation">;</span> <span class="token variable">$pattern</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"/w3school/i"</span><span class="token punctuation">;</span> <span class="token keyword">echo</span> <span class="token function">preg_match</span><span class="token punctuation">(</span><span class="token variable">$pattern</span><span class="token punctuation">,</span> <span class="token variable">$str</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>
使用 PREG_OFFSET_CAPTURE 找到输入字符串中匹配项的位置:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token variable">$str</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"Welcome to W3School"</span><span class="token punctuation">;</span> <span class="token variable">$pattern</span> <span class="token operator">=</span> <span class="token string double-quoted-string">"/w3school/i"</span><span class="token punctuation">;</span> <span class="token function">preg_match</span><span class="token punctuation">(</span><span class="token variable">$pattern</span><span class="token punctuation">,</span> <span class="token variable">$str</span><span class="token punctuation">,</span> <span class="token variable">$matches</span><span class="token punctuation">,</span> <span class="token constant">PREG_OFFSET_CAPTURE</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token function">print_r</span><span class="token punctuation">(</span><span class="token variable">$matches</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>