Session basics in Laravel - Step-by-Step Execution

Concept Flow - Session basics

User sends HTTP request

↓

Laravel reads session cookie

↓

Retrieve session data from storage

↓

Controller accesses/modifies session

↓

Laravel saves session data

↓

Response sent with updated session cookie

↓

User browser stores updated cookie

This flow shows how Laravel reads, modifies, and saves session data during a web request.

Execution Sample

Laravel

<?php
// Store data in session
session(['user_name' => 'Alice']);

// Retrieve data from session
$name = session('user_name');

// Remove data from session
session()->forget('user_name');

This code stores, retrieves, and removes a value in Laravel's session.

Execution Table

Step	Action	Session Data Before	Session Data After	Output/Result
1	Store 'user_name' => 'Alice'	{}	{"user_name": "Alice"}	No output
2	Retrieve 'user_name'	{"user_name": "Alice"}	{"user_name": "Alice"}	"Alice"
3	Remove 'user_name'	{"user_name": "Alice"}	{}	No output
4	Retrieve 'user_name' after removal	{}	{}	null (no value)

💡 Session data is empty after removal; retrieval returns null.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4
session data	{}	{"user_name": "Alice"}	{"user_name": "Alice"}	{}	{}
$name	undefined	undefined	"Alice"	"Alice"	null

Key Moments - 2 Insights

Why does retrieving 'user_name' after removal return null?

Because in step 3 the 'user_name' key is removed from the session, so in step 4 it no longer exists, returning null as shown in the execution_table.

Does storing data in session immediately output anything?

No, storing data in session (step 1) changes session storage but does not produce output, as shown by 'No output' in the execution_table.

Visual Quiz - 3 Questions

Look at the execution table, what is the session data after step 1?

A {"user_name": "Alice"}

B {}

C null

D {"user_name": null}

💡 Hint

Check the 'Session Data After' column for step 1 in the execution_table.

At which step does the session data become empty again?

A Step 2

B Step 3

C Step 4

D Step 1

💡 Hint

Look at the 'Session Data After' column to see when the session data changes to {}.

If you try to retrieve 'user_name' before storing it, what would you get?

A "Alice"

B Error

C null

D Empty string

💡 Hint

Refer to the variable_tracker for $name before step 1 and after step 4.

Concept Snapshot

Laravel sessions store data across requests.
Use session(['key' => value]) to save data.
Retrieve with session('key').
Remove with session()->forget('key').
Session data persists until removed or expired.

Full Transcript

In Laravel, sessions let you save data between web requests. When a user sends a request, Laravel reads the session cookie and loads stored data. You can store data using session(['key' => value]), retrieve it with session('key'), and remove it with session()->forget('key'). After changes, Laravel saves the session data and sends an updated cookie back to the browser. This way, data like user names or preferences stay available as the user moves through the site. The execution table shows storing 'user_name' as 'Alice', retrieving it, removing it, and then trying to retrieve again returns null because the data was removed.

Practice

1. What is the main purpose of sessions in Laravel?

easy

A. To store user data across multiple requests

B. To compile CSS and JavaScript files

C. To send emails to users

D. To manage database migrations

Solution

1. Step 1: Understand what sessions do

   Sessions keep user data while they browse your site, allowing data to persist between pages.

2. Step 2: Match purpose with options

   Only To store user data across multiple requests describes storing user data across requests, which is the session's role.

3. Final Answer:

   To store user data across multiple requests -> Option A

4. Quick Check:

   Sessions = store user data [OK]

Hint: Sessions keep data between pages, not for emails or files [OK]

Common Mistakes:

• Confusing sessions with asset compilation
• Thinking sessions send emails
• Mixing sessions with database tasks

2. Which of the following is the correct way to store a value in Laravel session?

easy

A. session('key' => 'value');

B. Session::put('key', 'value');

C. session()->put('key', 'value');

D. session->put('key', 'value');

Solution

1. Step 1: Recall Laravel session syntax

   To store data, use the session() helper with the put method: session()->put('key', 'value');

2. Step 2: Check each option

   A has syntax error (unexpected =>); B uses facade but not imported; C uses correct helper and method; D uses wrong arrow syntax.

3. Final Answer:

   session()->put('key', 'value'); -> Option C

4. Quick Check:

   Use session()->put() to store data [OK]

Hint: Use session() helper with ->put() to save data [OK]

Common Mistakes:

• Using invalid syntax like session('key' => 'value')
• Forgetting parentheses after session()
• Using wrong arrow (->) on session helper

3. What will be the output of this Laravel code?

session()->put('name', 'Alice');
$name = session('name');
echo $name;

medium

A. null

B. Alice

C. session

D. Error

Solution

1. Step 1: Store 'Alice' in session under 'name'

   The code uses session()->put('name', 'Alice') to save the value 'Alice'.

2. Step 2: Retrieve and echo the stored value

   session('name') fetches the value 'Alice' from session and echoes it.

3. Final Answer:

   Alice -> Option B

4. Quick Check:

   Stored value 'Alice' is retrieved and printed [OK]

Hint: session('key') gets stored value; here it prints 'Alice' [OK]

Common Mistakes:

• Expecting null if session not started
• Confusing session() helper with facade
• Assuming session() returns array

4. Identify the error in this Laravel session code:

session()->put('user', 'Bob');
session()->forget('users');

medium

A. No error, code works fine

B. Wrong method name, should be remove() instead of forget()

C. session() helper cannot be used with forget()

D. Key 'users' does not exist, so forget() does nothing

Solution

1. Step 1: Check stored and forgotten keys

   The code stores 'Bob' under 'user' but tries to forget 'users' (plural), which was never stored.

2. Step 2: Understand forget() behavior

   forget() silently does nothing if the key doesn't exist; no error occurs but the intended key is not removed.

3. Final Answer:

   Key 'users' does not exist, so forget() does nothing -> Option D

4. Quick Check:

   forget() on missing key does nothing [OK]

Hint: Check exact key names when using forget() [OK]

Common Mistakes:

• Assuming forget() throws error if key missing
• Confusing forget() with remove() method
• Thinking session() helper can't call forget()

5. You want to clear all session data for a user after logout. Which Laravel code correctly does this?

hard

A. session()->flush();

B. session()->clear();

C. session()->forgetAll();

D. session()->remove();

Solution

1. Step 1: Identify method to clear all session data

   Laravel's session()->flush() removes all session data for the current user.

2. Step 2: Verify other options

   Options B, C, and D are not valid Laravel session methods.

3. Final Answer:

   session()->flush(); -> Option A

4. Quick Check:

   Use flush() to clear all session data [OK]

Hint: Use flush() to clear entire session data [OK]

Common Mistakes:

• Using non-existent methods like clear() or forgetAll()
• Trying to remove session keys one by one instead of flush()
• Confusing forget() with flush()