PHP | What are cookies in PHP?
A cookie is a small piece of information store by the browser on the client location and sent to the server with every request. It stores a limited amount of data about 4kb(i.e.: 4096 bytes).
Create Cookies
A cookie is created with the setcookie() function.
setcookie(name, value, expire, path, domain, secure, httponly)
Parameters
| Parameter | Description | Which type of data |
|---|---|---|
| name | Name of the cookie. | String |
| value | Value of the cookie, stored in the client's computer. | String |
| expire | Unix timestamp, i.e. number of seconds since January 1st, 1970 (called as Unix Epoch). | Integer |
| path | Server path in which the cookie will be available. | String |
| domain | To which domain the cookie is available. | String |
| secure | If set true, the cookie is available over a secure connection only. | Boolean |
| httponly | If set true, the cookie is available over HTTP protocol only. Scripting languages like JavaScript won't be able to access the cookie. | Boolean |
Create/Retrieve a Cookie
<?php
$cookie_name = "user";
$cookie_value = "Devid Brooks";
setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/"); // 86400 = 1 day
?>
<html>
<head>Create/Retrieve a Cookie Example</head>
<body>
<?php
if(!isset($_COOKIE[$cookie_name])) {
echo "Cookie named '" . $cookie_name . "' is not set!";
} else {
echo "Cookie Name is:'" . $cookie_name . "'<br>";
echo "Cookie Value is: " . $_COOKIE[$cookie_name];
}
?>
</body>
</html>
Note: The setcookie() function must appear BEFORE the <html> tag.
Note: The value of the cookie is automatically URLencoded when sending the cookie, and automatically decoded when received (to prevent URLencoding, use setrawcookie() instead).
Modify a Cookie Value
To modify a cookie, just set (again) the cookie using the setcookie() function:
<?php
$cookie_name = "user";
$cookie_value = "Brono";
setcookie($cookie_name, $cookie_value, time() + (86400 * 30), "/"); // 86400 = 1 day
?>
<html>
<head>Modify a Cookie Value Example</head>
<body>
<?php
if(!isset($_COOKIE[$cookie_name])) {
echo "Cookie named '" . $cookie_name . "' is not set!";
} else {
echo "Cookie Name is:'" . $cookie_name . "'<br>";
echo "Cookie 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:
<?php
// set the expiration date to one hour ago
setcookie("user", "", time() - 3600);
?>
<html>
<head>Cookie Delete Example</head>
<body>
<?php
echo "Cookie 'user' is deleted.";
?>
</body>
</html>
Check if Cookies are Enabled
Below creates a small script that checks whether cookies are enabled.
<?php
setcookie("test_cookie", "test", time() + 3600, '/');
?>
<HTML>
<head>Check if Cookies are Enabled</head>
<body>
<?php
if(count($_COOKIE) > 0) {
echo "Cookies are enabled.";
} else {
echo "Cookies are disabled.";
}
?>
</body>
</html>
