strtoupper

例

すべての文字を大文字に変換します：

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token keyword">Echo</span> <span class="token function">Strtoupper</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>

自分で試してみてください