Introduction to Sessions and Cookies

What is the primary purpose of using sessions in PHP?

• To store data on the server for a specific user

• To track user preferences across multiple visits

• To store large amounts of data permanently

• To ensure that all users share the same data

Answer explanation

Sessions store user-specific data on the server across multiple requests, ensuring continuity for a user during their visit

What is a key difference between sessions and cookies?

• Sessions store data on the client-side, whereas cookies store data on the server

• Cookies expire after the browser is closed, while sessions persist indefinitely

• Sessions are stored on the server, whereas cookies are stored on the client

• Cookies cannot store user authentication details

Answer explanation

Sessions store data on the server and use a session ID to link the user, while cookies store data directly on the client’s browser

What PHP function is used to start a session?

• start_session()

• session_begin()

• session_start()

• init_session()

Answer explanation

session_start() initializes a session and must be called before any output is sent to the browser

Which of the following is TRUE about cookies?

• They are stored in the client’s browser

• They can store sensitive data securely

• They can be accessed using $_COOKIE in PHP

• They are deleted as soon as the user leaves the website

Answer explanation

Cookies are stored on the client’s browser and can be accessed in PHP using the $_COOKIE superglobal. However, they are not secure for storing sensitive data

How can you set a cookie in PHP?

• create_cookie('user', 'JohnDoe', time() + 3600);

• setcookie('user', 'JohnDoe', time() + 3600, '/');

• store_cookie('user', 'JohnDoe', time() + 3600);

• cookie_set('user', 'JohnDoe', time() + 3600);

Answer explanation

setcookie() is the correct function to create a cookie, with parameters specifying the name, value, expiration time, and path

How do you delete a cookie in PHP?

• deletecookie('user');

• setcookie('user', '', time() - 3600, '/');

• remove_cookie('user');

• unsetcookie('user');

Answer explanation

Setting the cookie’s expiration time to a past value removes it from the browser

What function is used to destroy a session?

• session_delete();

• session_end();

• session_unset(); session_destroy();

• session_remove();

Answer explanation

session_unset() clears the session variables, and session_destroy() terminates the session

Which PHP superglobal is used to retrieve session data?

• $_SESSION

• $_COOKIE

• $_REQUEST

• $_SERVER

Answer explanation

$_SESSION is used to access and manipulate session data

What is the default behavior of a PHP session when a browser is closed?

• It continues indefinitely

• It gets deleted automatically

• It remains stored in a cookie

• It refreshes and resets the session ID

Answer explanation

By default, PHP sessions are deleted when the browser is closed unless configured otherwise

How do you retrieve a cookie value in PHP?

• $_COOKIE['user']

• getcookie('user')

• cookie_get('user')

• $_SESSION['user']

Answer explanation

$_COOKIE['user'] accesses the cookie named "user"