# $\_COOKIE ## **$\_COOKIE** 设置和获取cookie值 ``` <pre class="calibre10">``` $_COOKIE<span class="token3">[</span><span class="token2">'id'</span><span class="token3">]</span><span class="token1">=</span><span class="token2">'dash_id'</span><span class="token3">;</span> $id<span class="token1">=</span>$_COOKIE<span class="token3">[</span><span class="token2">'id'</span><span class="token3">]</span><span class="token3">;</span> ``` ``` **延伸：** Cookie的配置与应用 ``` <pre class="calibre10">``` <span class="token4">Setcookie</span><span class="token3">(</span>string name<span class="token3">,</span> string value<span class="token3">,</span> int expire<span class="token3">,</span>string path<span class="token3">,</span> string domain<span class="token3">,</span> int secure<span class="token3">)</span><span class="token3">;</span> ``` ``` name是cookie变量名称标识，你在php中将能象使用普通变量名相同来用他引用cookie变量。 value是cookie变量的初始值， expire 表示该cookie变量的有效时间； path 为该cookie变量的相关路径； domain 表示cookie变量的网站； secure 则需在 https 的安全传输时才有效 **删除Cookie** ``` <pre class="calibre10">``` <span class="token4">SetCookie</span><span class="token3">(</span><span class="token2">"Cookie"</span><span class="token3">,</span> <span class="token2">""</span><span class="token3">)</span><span class="token3">;</span> <span class="token">//或者</span> <span class="token4">SetCookie</span><span class="token3">(</span><span class="token2">"Cookie"</span><span class="token3">,</span> <span class="token2">"value"</span> <span class="token3">,</span> <span class="token4">time</span><span class="token3">(</span><span class="token3">)</span><span class="token1">-</span><span class="token6">1</span> <span class="token1">/</span> <span class="token4">time</span><span class="token3">(</span><span class="token3">)</span> <span class="token3">)</span><span class="token3">;</span> ``` ``` 使用Cookie的限制 > 1、必须在HTML文件的内容输出之前设置； > 2、不同的浏览器对Cookie的处理不一致，且有时会出现错误的结果。 > 3、限制是在客户端的。一个浏览器能创建的Cookie数量最多为30个，并且每个不能超过4KB，每个WEB站点能设置的Cookie总数不能超过20个