get_defined_vars

实例

以数组形式返回所有定义的变量：

<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 punctuation">;</span>

<span class="token variable">$arr</span> <span class="token operator">=</span> <span class="token function">get_defined_vars</span><span class="token punctuation">(</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 variable">$arr</span><span class="token punctuation">[</span><span class="token string double-quoted-string">"a"</span><span class="token punctuation">]</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

亲自试一试

例子解释：

在这个例子中，$a 是一个包含三个颜色字符串的数组。调用 get_defined_vars() 后，它返回一个数组 $arr，该数组包含当前作用域中定义的所有变量。然后通过 print_r($arr["a"]) 输出 $a 变量的内容，即颜色数组。请注意，get_defined_vars() 返回的数组键是变量名，对应的值是变量的值。