Home >Backend Development >PHP Problem >What does Cookie mean in PHP?
Cookie is often used to identify users. It is a small file left by the server on the user's computer. Whenever the same computer requests a page through the browser, this computer will send the Cookie. Through PHP, the user can Create and retrieve cookie values.
Recommended tutorial: "PHP Cookie-based Shopping Cart Module Design"
How to create a cookie?
The setcookie() function is used to set cookies.
Note: The setcookie() function must be located before the 100db36a723c770d327fc0aef2ce13b1 tag.
Syntax
setcookie(name, value, expire, path, domain);
Example 1
In the following example, we will create a cookie named "user" and assign it the value "runoob". We also specify that this cookie expires after one hour:
<?php
setcookie("user", "runoob", time()+3600);
?>
<html>
.....Note: The cookie value is automatically URL-encoded when sending the cookie and automatically decoded when retrieved. (To prevent URL encoding, use setrawcookie() instead.)
Example 2
You can also set the cookie expiration time in another way. This may be simpler than using seconds.
<?php
$expire=time()+60*60*24*30;
setcookie("user", "runoob", $expire);
?>
<html>
.....In the above example, the expiration time is set to one month (60 seconds * 60 minutes * 24 hours * 30 days).
How to retrieve the value of Cookie?
PHP’s $_COOKIE variable is used to retrieve the value of the cookie.
In the following example, we retrieve the value of the cookie named "user" and display it on the page:
<?php // 输出 cookie 值 echo $_COOKIE["user"]; // 查看所有 cookie print_r($_COOKIE); ?>
In the following example, we use isset() function to confirm whether the cookie has been set:
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>
<?php
if (isset($_COOKIE["user"]))
echo "欢迎 " . $_COOKIE["user"] . "!<br>";
else
echo "普通访客!<br>";
?>
</body>
</html>How to delete cookies?
When deleting a cookie, you should change the expiration date to a point in time in the past.
Deleted instance:
<?php
// 设置 cookie 过期时间为过去 1 小时
setcookie("user", "", time()-3600);
?>Recommended tutorial: "PHP Tutorial"
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