array_search

配列内の指定された値を検索し、成功した場合は、最初の対応するキー名を返します

名前:array_search

カテゴリ:配列

対応言語:php

一言説明:配列内の指定された値を検索し、キー名を返します。

例

例1

配列でキー値「赤」を検索し、そのキー名を返します。

 <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 punctuation">;</span>
<span class="token keyword">エコー</span><span class="token function"></span></span><mark><span class="token function">array_search</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"red"</span> <span class="token punctuation">、</span> <span class="token variable">$ a</span> <span class="token punctuation">）</span></mark><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

配列でキー値5を検索し、キー名を返します（ ""）：

 <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">"5"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"b"</span> <span class="token operator">=></span> <span class="token number">5</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">"5"</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token keyword">エコー</span><span class="token function"></span></span><mark><span class="token function">array_search</span> <span class="token punctuation">（</span> <span class="token number">5</span> <span class="token punctuation">、</span> <span class="token variable">$ a</span> <span class="token punctuation">、</span> <span class="token constant boolean">true</span> <span class="token punctuation">）</span></mark><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