Single action controllers in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this single action controller?

Consider this Laravel single action controller. What will be the HTTP response content when this controller is called?

Laravel

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class WelcomeController
{
    public function __invoke(Request $request)
    {
        return response('Hello, Laravel!');
    }
}

A A 404 Not Found error response

B A redirect response to the home page '/'

C A plain text HTTP response with content 'Hello, Laravel!'

D A JSON response with content {"message": "Hello, Laravel!"}

💡 Hint

Single action controllers use the __invoke method to handle requests.

The __invoke method returns a plain text response with the string 'Hello, Laravel!'. This is the content the client receives.

📝 Syntax

intermediate

Which option correctly defines a single action controller in Laravel?

Select the code snippet that correctly defines a single action controller class in Laravel.

A class UserController { public function __invoke() { return 'User'; } }

B class UserController { public function handle() { return 'User'; } }

C class UserController { public function index() { return 'User'; } }

D class UserController { public function __call() { return 'User'; } }

💡 Hint

Single action controllers use the magic __invoke method.

Only the __invoke method allows the controller to be called as a single action.

❓ state_output

advanced

What is the output after calling this single action controller with a request?

Given this controller, what will be the output when accessed via a web route?

Laravel

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class CounterController
{
    private int $count = 0;

    public function __invoke(Request $request)
    {
        $this->count++;
        return "Count is: {$this->count}";
    }
}

A Count is: 1

B Count is: 2

C Count is: 0

D Error: Cannot access private property

💡 Hint

Each request creates a new controller instance.

The count starts at 0 and increments once per request. Since each request is new, count is always 1.

🔧 Debug

advanced

Why does this single action controller cause a routing error?

This controller is registered in routes/web.php as Route::get('/test', TestController::class); but accessing '/test' gives a 500 error. What is the problem?

Laravel

<?php

namespace App\Http\Controllers;

class TestController
{
    public function handle()
    {
        return 'Test';
    }
}

A The controller namespace is incorrect.

B The handle method is private and cannot be accessed.

C The route should use a closure, not a controller class.

D The controller lacks an __invoke method required for single action controllers.

💡 Hint

Single action controllers must have __invoke method.

When routing to a controller class without specifying a method, Laravel calls __invoke. Missing it causes error.

🧠 Conceptual

expert

What is a key advantage of using single action controllers in Laravel?

Choose the best explanation for why developers use single action controllers.

A They enable automatic database migrations when routes are registered.

B They simplify controllers by focusing on one action, improving readability and testability.

C They automatically cache responses without extra code.

D They allow multiple HTTP methods to be handled in one controller method.

💡 Hint

Think about controller responsibilities and code clarity.

Single action controllers have one job, making code easier to read, maintain, and test.