Cookie handling in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this Laravel cookie retrieval code?

Consider this Laravel controller method that tries to read a cookie named 'user_id'. What will be the output if the cookie does not exist?

Laravel

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class CookieController extends Controller
{
    public function showUserId(Request $request)
    {
        $userId = $request->cookie('user_id', 'guest');
        return response()->json(['user_id' => $userId]);
    }
}

A {"user_id":null}

B {"user_id":""}

C {"user_id":"guest"}

D Throws an exception because cookie 'user_id' is missing

💡 Hint

Check the second parameter of the cookie() method in the Request object.

The cookie() method on the Request object returns the cookie value if it exists. If it does not, it returns the default value provided as the second argument. Here, 'guest' is the default, so the output JSON will have 'user_id' set to 'guest'.

📝 Syntax

intermediate

Which option correctly sets a cookie in Laravel with a 10-minute expiration?

You want to set a cookie named 'theme' with value 'dark' that expires in 10 minutes. Which code snippet correctly does this?

A return response('Set theme')->cookie('theme', 'dark', 10);

B return response('Set theme')->cookie('theme', 'dark', now()->addMinutes(10));

C return response('Set theme')->cookie('theme', 'dark', 600);

D return response('Set theme')->cookie('theme', 'dark', '10m');

💡 Hint

The third parameter is the number of minutes until expiration.

In Laravel, the cookie() method's third parameter is the duration in minutes. So passing 10 sets the cookie to expire in 10 minutes. Passing a string like '10m' is invalid.

🔧 Debug

advanced

Why does this Laravel code fail to delete the cookie?

This code tries to delete a cookie named 'session_id' but the cookie remains in the browser. What is the reason?

Laravel

<?php

return response('Delete cookie')->cookie('session_id', '', -1);

A Negative expiration time is invalid and causes Laravel to ignore the cookie.

B The cookie path or domain does not match the original cookie, so deletion fails.

C Setting the cookie value to empty string does not delete it; must use null instead.

D Cookies cannot be deleted via response; must be deleted client-side with JavaScript.

💡 Hint

Cookies are deleted by setting expiration in the past but path and domain must match.

To delete a cookie, Laravel sets it with an expiration time in the past. However, if the path or domain differs from the original cookie, the browser will not delete it. This is a common cause of cookie deletion failure.

❓ state_output

advanced

What is the value of the cookie after this Laravel middleware runs?

This middleware adds a cookie named 'visited' with value 'yes' on the first request. What will be the cookie value on the second request?

Laravel

<?php

namespace App\Http\Middleware;

use Closure;

class CheckVisited
{
    public function handle($request, Closure $next)
    {
        if (!$request->cookie('visited')) {
            $response = $next($request);
            return $response->cookie('visited', 'yes', 60);
        }
        return $next($request);
    }
}

A On second request, cookie 'visited' has value 'yes'.

B On second request, cookie 'visited' is null because middleware does not set it again.

C On second request, middleware throws an error because cookie is missing.

D On second request, cookie 'visited' has value 'no'.

💡 Hint

Cookies set in response are sent to browser and included in next request.

On the first request, the cookie 'visited' is not present, so middleware sets it with value 'yes'. The browser stores it and sends it back on the second request, so the cookie exists with value 'yes'.

🧠 Conceptual

expert

Which statement about Laravel cookie encryption is true?

Laravel encrypts cookies by default. Which of these statements correctly describes this behavior?

A Cookies are encrypted only if the app is in production environment.

B Cookies must be manually encrypted before setting them in Laravel responses.

C Laravel does not encrypt cookies; encryption must be handled by the developer.

D Cookies are encrypted automatically unless added to the 'except' list in the EncryptCookies middleware.

💡 Hint

Check the EncryptCookies middleware behavior in Laravel.

Laravel automatically encrypts all cookies except those listed in the $except array of the EncryptCookies middleware. This ensures cookie data is secure by default.