filter_has_var
检查指定类型的变量是否存在
简体中文
简体中文
在本例中，输入变量 "name" 被发送到 PHP 页面：
<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token keyword">if</span><span class="token punctuation">(</span><span class="token operator">!</span><span class="token function"></span><mark><span class="token function">filter_has_var</span><span class="token punctuation">(</span><span class="token constant">INPUT_GET</span><span class="token punctuation">,</span> <span class="token string double-quoted-string">"name"</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 keyword">echo</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"Input type does not exist"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token keyword">else</span>
<span class="token punctuation">{</span>
<span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token string double-quoted-string">"Input type exists"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token delimiter important">?></span></span>
输出类似：
Input type exists
filter_var_array
filter_input
filter_has_var
filter_list
filter_input_array
filter_var
filter_id
