Sessions & Cookies
Sessions
Sessions are the super global variables which can be used across the multiple pages in a website. Session variables hold information about the user and help in carrying that information on various web pages of that website. Sessions create a temporary directory on the server which stores the variables and its values.
How to start php session
A session is started using session_start()
method and the variables are set using $_SESSION
variable.
Code example using session_start()
<?php
session_start();
$_SESSION['username'] = 'abcd';
$_SESSION['userID'] = 1234;
echo 'WELCOME '.$_SESSION['username'];
?>
<!-- OUTPUT:
WELCOME abcd
-->
How to destroy php session
A session can be destroyed using session_unset()
and session_destroy()
method.
session_unset(); // remove all session variables
session_destroy(); // destroy the session
Cookies
A cookie is also used to check for an authenticated user. A cookie is a small file which is embedded to the user’s system. It is sent along with the page request by the user to the server.
// syntax
setcookie(name, value, expiry, path, domain, secure, httponly);
// name parameter is required only
<?php
$name = "user";
$value = "John Doe";
setcookie($name, $value, time() + (86400 * 30), "/"); // 86400 = 1 day
if(!isset($_COOKIE[$name])) {
echo $name . " Cookie is not set!";
} else{
echo $name . " Cookie is set!<br>";
}
?>