Setting and reading cookies in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a cookie in web development?

A cookie is a small piece of data stored on the user's computer by the web browser. It helps websites remember information about the user, like login status or preferences.

beginner

How do you set a cookie in PHP?

You use the setcookie() function. For example: setcookie('user', 'Alice', time() + 3600); sets a cookie named 'user' with value 'Alice' that expires in 1 hour.

beginner

How do you read a cookie value in PHP?

You read cookies from the $_COOKIE superglobal array. For example: $user = $_COOKIE['user'] ?? 'Guest'; gets the 'user' cookie or 'Guest' if it doesn't exist.

intermediate

What must you remember about when to call setcookie() in PHP?

You must call setcookie() before any output is sent to the browser, because it sends HTTP headers. If you print or echo anything first, setting cookies will fail.

intermediate

How can you delete a cookie in PHP?

To delete a cookie, set it with an expiration time in the past. For example: setcookie('user', '', time() - 3600); tells the browser to remove the 'user' cookie.

Which PHP function is used to set a cookie?

A cookie_set()

B setcookie()

C set_cookie()

D cookie()

The correct function to set a cookie in PHP is setcookie().

Where are cookies stored?

A On the user's computer

B On the web server

C In the PHP script

D In the database

Cookies are stored on the user's computer by the web browser.

How do you access a cookie named 'session' in PHP?

A $_SESSION['session']

B getcookie('session')

C $_COOKIE['session']

D cookie('session')

Cookies are accessed using the $_COOKIE array, like $_COOKIE['session'].

What happens if you call setcookie() after outputting HTML?

A The cookie will be deleted

B Cookie will be set normally

C PHP will automatically buffer output and set cookie

D Cookie will not be set because headers are already sent

Cookies require HTTP headers, so calling setcookie() after output causes failure.

How do you delete a cookie named 'user'?

A setcookie('user', '', time() - 3600);

B unset($_COOKIE['user']);

C setcookie('user', null);

D delete_cookie('user');

To delete a cookie, set it with an expiration time in the past using setcookie().

Explain how to set and read a cookie in PHP with an example.

Think about how you tell the browser to save data and then how you get it back.

What are the important rules to remember when working with cookies in PHP?

Consider timing and how cookies expire or get removed.