A cookie is often used to identify a user. A cookie is a small file that the server embeds on the user's computer. Each time the same computer requests a page with a browser, it will send the cookie too. With PHP, you can both create and retrieve cookie values.
How to Create a Cookie?
The setcookie() function is used to set a cookie.
Note: The setcookie() function must appear BEFORE the <html> tag.
setcookie(name, value, expire, path, domain);
In the example below, we will create a cookie named "user" and assign the value "Alex Porter" to it. We also specify that the cookie should expire after one hour:
When deleting a cookie you should assure that the expiration date is in the past.
// set the expiration date to one hour ago
setcookie("user", "", time()-3600);
What if a Browser Does NOT Support Cookies?
If your application deals with browsers that do not support cookies, you will have to use other methods to pass information from one page to another in your application. One method is to pass the data through forms (forms and user input are described earlier in this tutorial).
The form below passes the user input to "welcome.php" when the user clicks on the "Submit" button:
<form action="welcome.php" method="post">
Name: <input type="text" name="name" />
Age: <input type="text" name="age" />
<input type="submit" />
</html> Retrieve the values in the "welcome.php" file like this:
Welcome <?php echo $_POST["name"]; ?>.<br />
You are <?php echo $_POST["age"]; ?> years old.