array_unshift

名称:array_unshift

分类:数组

所属语言:php

一句话介绍:在数组开头插入一个或多个元素。

实例

例子 1

把元素 "blue" 插入数组中：

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

显示返回值：

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

使用数字键名：

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token variable">$a</span><span class="token operator">=</span><span class="token keyword">array</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token operator">=></span><span class="token string double-quoted-string">"red"</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token operator">=></span><span class="token string double-quoted-string">"green"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token function"></span><mark><span class="token function">array_unshift</span><span class="token punctuation">(</span><span class="token variable">$a</span><span class="token punctuation">,</span><span class="token string double-quoted-string">"blue"</span><span class="token punctuation">)</span></mark><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 variable">$a</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

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