sizeof

例

例1

配列内の要素の数を返します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token variable">$ cars</span> <span class="token operator">=</span> <span class="token keyword">array</span> <span class="token punctuation">（</span> <span class="token string double-quoted-string">"volvo"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"bmw"</span> <span class="token punctuation">、</span> <span class="token string double-quoted-string">"トヨタ"</span> <span class="token punctuation">）</span> <span class="token punctuation">;</span>
<span class="token keyword"></span></span><mark><span class="token keyword">エコー</span><span class="token function">サイズ</span><span class="token punctuation">（</span> <span class="token variable">$ cars</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

配列内の要素の数を再帰的に計算します。

 <span class="token php language-php"><span class="token delimiter important"><？php</span>
<span class="token variable">$ cars</span> <span class="token operator">=</span> <span class="token keyword">array</span>
  <span class="token punctuation">（</span>
  <span class="token string double-quoted-string">「Volvo」</span> <span class="token operator">=></span><span class="token keyword">配列</span>
  <span class="token punctuation">（</span>
  <span class="token string double-quoted-string">「xc60」</span> <span class="token punctuation">、</span>
  <span class="token string double-quoted-string">「xc90」</span>
  <span class="token punctuation">）</span> <span class="token punctuation">、、</span>
  <span class="token string double-quoted-string">「BMW」</span> <span class="token operator">=></span><span class="token keyword">配列</span>
  <span class="token punctuation">（</span>
  <span class="token string double-quoted-string">「x3」</span> <span class="token punctuation">、</span>
  <span class="token string double-quoted-string">「x5」</span>
  <span class="token punctuation">）</span> <span class="token punctuation">、、</span>
  <span class="token string double-quoted-string">「トヨタ」</span> <span class="token operator">=></span><span class="token keyword">配列</span>
  <span class="token punctuation">（</span>
  <span class="token string double-quoted-string">「ハイランダー」</span>
  <span class="token punctuation">））</span>
  <span class="token punctuation">）</span> <span class="token punctuation">;</span>

<span class="token keyword">エコー</span><span class="token string double-quoted-string">「一般的なカウント：」</span> <span class="token operator">。</span><span class="token function"></span></span><mark> <span class="token function">sizeof</span> <span class="token punctuation">（</span> <span class="token variable">$ cars</span> <span class="token punctuation">）</span></mark><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">エコー</span><span class="token string double-quoted-string">「再帰カウント：」</span> <span class="token operator">。</span><span class="token function"></span><mark> <span class="token function">sizeof</span> <span class="token punctuation">（</span> <span class="token variable">$ cars</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 delimiter important">？></span>

自分で試してみてください