strrev
反转一个字符串
反转字符串 "I love Shanghai!":
<span class="token php language-php"><span class="token delimiter important"><?php</span> <span class="token keyword">echo</span> <span class="token function">strrev</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"I love Shanghai!"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token delimiter important">?></span></span>