strtolower

实例

把所有字符转换为小写：

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token keyword">echo</span> <span class="token function">strtolower</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"Hello WORLD."</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

亲自试一试