array_rand

例

例1

ランダムなキー名を含む配列を返します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token variable">$ a</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"green"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"blue"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"Yellow"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"Brown"</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token variable">$ random_keys</span> <span class="token operator">=</span><span class="token function"></span></span><mark> <span class="token function">array_rand</span> <span class="token punctuation">（</span> <span class="token variable">$ a</span> <span class="token punctuation">、</span> <span class="token number">3</span> <span class="token punctuation">）</span></mark><span class="token punctuation"></span> <span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token variable">$ a</span> <span class="token punctuation">[</span> <span class="token variable">$ random_keys</span> <span class="token punctuation">[</span> <span class="token number">0</span> <span class="token punctuation">]</span> <span class="token punctuation">]</span> <span class="token operator">。</span> <span class="token string double-quoted-string">"<br>"</span> <span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token variable">$ a</span> <span class="token punctuation">[</span> <span class="token variable">$ random_keys</span> <span class="token punctuation">[</span> <span class="token number">1</span> <span class="token punctuation">]</span> <span class="token punctuation">]</span> <span class="token operator">。</span> <span class="token string double-quoted-string">"<br>"</span> <span class="token punctuation">;</span>
<span class="token keyword">echo</span> <span class="token variable">$ a</span> <span class="token punctuation">[</span> <span class="token variable">$ random_keys</span> <span class="token punctuation">[</span> <span class="token number">2</span> <span class="token punctuation">]</span> <span class="token punctuation">]</span> <span class="token punctuation">;</span>
<span class="token delimiter important">？></span>

自分で試してみてください

例2

配列からランダムキーを返します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token variable">$ a</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"a"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"b"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"green"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"c"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"blue"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"d"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"Yellow"</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 function"></span></span><mark> <span class="token function">array_rand</span> <span class="token punctuation">（</span> <span class="token variable">$ a</span> <span class="token punctuation">、</span> <span class="token number">1</span> <span class="token punctuation">）</span></mark><span class="token punctuation"></span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token delimiter important">？></span>

自分で試してみてください

例3

ランダムな文字列キー名を含む配列を返します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token variable">$ a</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"a"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"b"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"green"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"c"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"blue"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"d"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"Yellow"</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 function"></span></span><mark> <span class="token function">array_rand</span> <span class="token punctuation">（</span> <span class="token variable">$ a</span> <span class="token punctuation">、</span> <span class="token number">2</span> <span class="token punctuation">）</span></mark><span class="token punctuation"></span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token delimiter important">？></span>

自分で試してみてください