array_map

名前:array_map

カテゴリ:配列

対応言語:php

一言説明:配列内の各値をユーザー定義の関数に送信し、新しい値を返します。

例

例1

アレイ内の各値に関数を適用し、各値を単独で乗算し、新しい値を使用して配列を返します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token keyword">機能</span><span class="token function-definition function">myfunction</span> <span class="token punctuation">（</span> <span class="token variable">$ v</span> <span class="token punctuation">）</span>
<span class="token punctuation">{</span>
  <span class="token keyword">return</span> <span class="token punctuation">（</span> <span class="token variable">$ v</span> <span class="token operator">*</span> <span class="token variable">$ v</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token variable">$</span> <span class="token punctuation">a</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token number">1、2、3、4、5</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span><span class="token number"></span><span class="token number"></span><span class="token number"></span><span class="token punctuation"></span><span class="token number"></span><span class="token punctuation"></span><span class="token punctuation"></span>
<span class="token function">print_r</span> <span class="token punctuation">（</span><span class="token function"></span></span><mark> <span class="token function">array_map</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"myfunction"</span> <span class="token punctuation">、</span> <span class="token variable">$ a</span> <span class="token punctuation">）</span></mark><span class="token punctuation"></span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token delimiter important">？></span>

自分で試してみてください

例2

ユーザー定義の関数を使用して、配列の値を変更します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token keyword">機能</span><span class="token function-definition function">myfunction</span> <span class="token punctuation">（</span> <span class="token variable">$ v</span> <span class="token punctuation">）</span>
<span class="token punctuation">{</span>
<span class="token keyword">if</span> <span class="token punctuation">（</span> <span class="token variable">$ v</span> <span class="token operator">===</span> <span class="token string double-quoted-string">"dog"</span> <span class="token punctuation">）</span>
  <span class="token punctuation">{</span>
  <span class="token string double-quoted-string">「fido」</span><span class="token keyword">を返します</span><span class="token punctuation">。</span>
  <span class="token punctuation">}</span>
<span class="token variable">$ v</span><span class="token keyword">を返します</span><span class="token punctuation">。</span>
<span class="token punctuation">}</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">"horse"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"dog"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"cat"</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_map</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"myfunction"</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 punctuation">;</span>
<span class="token delimiter important">？></span>

自分で試してみてください

例3

2つの配列を使用します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token keyword">機能</span><span class="token function-definition function">myfunction</span> <span class="token punctuation">（</span> <span class="token variable">$ v1</span> <span class="token punctuation">、</span> <span class="token variable">$ v2</span> <span class="token punctuation">）</span>
<span class="token punctuation">{</span>
<span class="token keyword">if</span> <span class="token punctuation">（</span> <span class="token variable">$ v1</span> <span class="token operator">===</span> <span class="token variable">$ v2</span> <span class="token punctuation">）</span>
  <span class="token punctuation">{</span>
  <span class="token string double-quoted-string">「同じ」</span><span class="token keyword">を返します</span><span class="token punctuation">。</span>
  <span class="token punctuation">}</span>
<span class="token string double-quoted-string">「違う」</span><span class="token keyword">を返します</span><span class="token punctuation">。</span>
<span class="token punctuation">}</span>

<span class="token variable">$ a1</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"horse"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"dog"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"cat"</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token variable">$ a2</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"cow"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"dog"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"rat"</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_map</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"myfunction"</span> <span class="token punctuation">、</span> <span class="token variable">$ a1</span> <span class="token punctuation">、</span> <span class="token variable">$ a2</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4

アレイ内の値のすべての文字を大文字に変更します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token keyword">機能</span><span class="token function-definition function">myfunction</span> <span class="token punctuation">（</span> <span class="token variable">$ v</span> <span class="token punctuation">）</span>
<span class="token punctuation">{</span>
<span class="token variable">$ v</span> <span class="token operator">=</span> <span class="token function">strtoupper</span> <span class="token punctuation">（</span> <span class="token variable">$ v</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
  <span class="token variable">$ v</span><span class="token keyword">を返します</span><span class="token punctuation">。</span>
<span class="token punctuation">}</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">"animal"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"horse"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"type"</span> <span class="token operator">=></span> <span class="token string double-quoted-string">"哺乳類"</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">array_map</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"myfunction"</span> <span class="token punctuation">、</span> <span class="token variable">$ a</span> <span class="token punctuation">）</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

例5

関数名をnullに割り当てるとき：

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token variable">$ a1</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"dog"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"cat"</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token variable">$ a2</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"puppy"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"kitten"</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_map</span> <span class="token punctuation">（</span> <span class="token constant">null</span> <span class="token punctuation">、</span> <span class="token variable">$ a1</span> <span class="token punctuation">、</span> <span class="token variable">$ a2</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