Cookies
- 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.
Create Cookies With PHP
A cookie is created with the
setcookie() function.Syntax
setcookie(name, value, expire, path, domain, secure, httponly);
Only the name parameter is required. All other parameters are optional.
PHP Create/Retrieve a Cookie
The following example creates a cookie named "user" with the value "John Doe". The cookie will expire after 30 days (86400 * 30).
We then retrieve the value of the cookie "user" (using the global variable $_COOKIE). We also use the
isset() function to find out if the cookie is set:Example
<?php
$cookie_name = "user";
$cookie_value = "John Doe";
setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/"); // 86400 = 1 day?>
<html>
<body>
<?php
if(!isset($_COOKIE[$cookie_name])) {
echo "Cookie named '" . $cookie_name . "' is not set!";
} else {
echo "Cookie '" . $cookie_name . "' is set!<br>";
echo "Value is: " . $_COOKIE[$cookie_name];
}
?>
</body>
</html>
Note: The setcookie() function must appear BEFORE the <html> tag.
Modify a Cookie Value
To modify a cookie, just set (again) the cookie using the
setcookie() function:Example
<?php
$cookie_name = "user";
$cookie_value = "Alex Porter";
setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/");
?>
<html>
<body>
<?php
if(!isset($_COOKIE[$cookie_name])) {
echo "Cookie named '" . $cookie_name . "' is not set!";
} else {
echo "Cookie '" . $cookie_name . "' is set!<br>";
echo "Value is: " . $_COOKIE[$cookie_name];
}
?>
</body>
</html>
Delete a Cookie
To delete a cookie, use the
setcookie() function with an expiration date in the past:Example
<?php
// set the expiration date to one hour agosetcookie("user", "", time() - 3600);
?>
<html>
<body>
<?php
echo "Cookie 'user' is deleted.";
?>
</body>
</html>
Check if Cookies are Enabled
The following example creates a small script that checks whether cookies are enabled. First, try to create a test cookie with the
setcookie() function, then count the $_COOKIE array variable:Example
<?php
setcookie("test_cookie", "test", time() + 3600, '/');
?>
<html>
<body>
<?php
if(count($_COOKIE) > 0) {
echo "Cookies are enabled.";
} else {
echo "Cookies are disabled.";
}
?>
</body>
</html>