Starting and using sessions in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a session in PHP?

A session in PHP is a way to store information (variables) to be used across multiple pages. It helps keep user data while they browse a website.

beginner

How do you start a session in PHP?

Use the function session_start(); at the very beginning of your PHP script before any output. This creates or resumes a session.

beginner

How do you store data in a PHP session?

You store data by assigning values to the $_SESSION superglobal array, like $_SESSION['key'] = 'value';.

beginner

How do you access session data on another page?

First, call session_start(); on the page, then read the data from $_SESSION['key'].

intermediate

What must you avoid before calling session_start();?

You must avoid sending any output (like HTML or echo) before session_start(); because it sends HTTP headers.

Which PHP function starts or resumes a session?

A session_start()

B start_session()

C begin_session()

D init_session()

The correct function to start or resume a session in PHP is session_start().

Where should session_start() be placed in your PHP script?

A After HTML output

B Anywhere in the script

C Before any output

D Inside a function only

session_start() must be called before any output to avoid header errors.

How do you store a user's name in a session variable?

A set_session('name', 'John');

B session['name'] = 'John';

C session->name = 'John';

D $_SESSION['name'] = 'John';

Use the superglobal array $_SESSION to store session data like $_SESSION['name'] = 'John';.

What happens if you try to access $_SESSION without calling session_start()?

A You get an error or empty data

B Session data is automatically loaded

C Session is created automatically

D Nothing happens, it works fine

Without session_start(), PHP does not load session data, so $_SESSION will be empty or cause errors.

Which superglobal array holds session variables?

A $_POST

B $_SESSION

C $_GET

D $_COOKIE

Session variables are stored in the $_SESSION superglobal array.

Explain how to start a session and store a user's favorite color in PHP.

Remember to start the session first, then save data in $_SESSION.

Describe why it is important to call session_start() before any output in PHP.

Think about how PHP sends session cookies in headers.