javascript 如果 cookie 不存在警报和重定向
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If cookie does not exist alert and redirect
提问by Satch3000
I need to check if a cookie exists when the user lands on a page and if the cookie does not exist I need to popup an alert and then redirect to another page.
当用户登陆页面时，我需要检查 cookie 是否存在，如果 cookie 不存在，我需要弹出警报，然后重定向到另一个页面。
回答by Mala
if( $.cookie('cookiename') == null ) {
alert("OH NOES U NO HAS COOKIE");
window.location.replace('http://url');
}
回答by Niet the Dark Absol
if( document.cookie.indexOf("cookiename=") < 0) {
alert("Cookie not found, redirecting you.");
location.href = "newpage.html";
}
Be careful not to use a cookie name that may be the end of another cookie name. If this is likely, you'll need to do a full cookie read, or use PHP instead.
注意不要使用可能是另一个 cookie 名称结尾的 cookie 名称。如果这是可能的，您将需要执行完整的 cookie 读取，或者改用 PHP。
回答by Satch3000
Using JavascriptReadCookie()Function
使用JavascriptReadCookie()功能
ReadCookie(), you realize immediately, is used to read a cookie.
ReadCookie()，你马上意识到，是用来读取cookie的。
You can read any cookies, provided they are being read on the same domain they were set at.
您可以读取任何 cookie，只要它们是在它们设置的同一个域上读取的。
<script type="text/javascript" language="JavaScript">
var acookie = ReadCookie("cookiename");
if(acookie.length == 0)
{
//redirect somewhere
}
</script>
