strpos
查找字符串中子字符串第一次出现的位置
查找 "php" 在字符串中第一次出现的位置:
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span> <span class="token function">strpos</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"You love php, I love php too!"</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"php"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>