array_rand

名称:array_rand

分类:数组

所属语言:php

一句话介绍:返回数组中一个或多个随机的键。

实例

例子 1

返回包含随机键名的数组：

<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><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></span>

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例子 2

从数组返回一个随机键：

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

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例子 3

返回包含随机字符串键名的数组：

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

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