API routes in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this Laravel API route response?

Consider this Laravel API route code. What JSON response will the client receive when accessing /api/user?

Laravel

<?php

use Illuminate\Http\Request;
use Illuminate\Support\Facades\Route;

Route::get('/user', function (Request $request) {
    return response()->json(['name' => 'Alice', 'role' => 'admin']);
});

A {"name":"Alice"}

B {"user":{"name":"Alice","role":"admin"}}

C SyntaxError: Unexpected token in JSON

D {"name":"Alice","role":"admin"}

💡 Hint

Look at the array passed to response()->json() and how it converts to JSON.

The route returns a JSON response with keys 'name' and 'role' directly, so the output is a JSON object with those keys and values.

📝 Syntax

intermediate

Which option correctly defines a POST API route in Laravel?

You want to create a POST API route at /api/login that calls LoginController@login. Which option is correct?

A Route::post('/login', 'LoginController@login');

B Route::get('/login', [LoginController::class, 'login']);

C Route::post('/login', [LoginController::class, 'login']);

D Route::post('/login', function() { return LoginController@login(); });

💡 Hint

Use the array syntax with the controller class and method for API routes.

Option C uses the correct HTTP verb 'post' and the recommended array syntax with the controller class and method name.

🔧 Debug

advanced

Why does this Laravel API route return a 404 error?

Given this route definition, why does accessing /api/profile return a 404 error?

Route::get('/user/profile', function() {
    return ['profile' => 'data'];
});

A The route URL is '/user/profile', so '/api/profile' does not match and returns 404.

B The route is missing a controller, so it cannot be found.

C The route method should be post, not get, for '/api/profile'.

D The route callback returns an array instead of a JSON response, causing 404.

💡 Hint

Check the exact URL path defined in the route and the URL you are accessing.

The route is defined for '/user/profile', but the request is to '/api/profile'. They do not match, so Laravel returns 404.

❓ state_output

advanced

What is the output of this Laravel API route with middleware?

This route uses the 'auth:sanctum' middleware. What happens when an unauthenticated user accesses /api/dashboard?

Route::middleware('auth:sanctum')->get('/dashboard', function () {
    return ['message' => 'Welcome to your dashboard'];
});

A HTTP 404 Not Found error

B HTTP 401 Unauthorized error response

C {"message":"Welcome to your dashboard"}

D HTTP 500 Internal Server Error

💡 Hint

Middleware 'auth:sanctum' requires authentication before allowing access.

If the user is not authenticated, the 'auth:sanctum' middleware blocks access and returns a 401 Unauthorized response.

🧠 Conceptual

expert

How does Laravel API route caching affect route changes?

You run php artisan route:cache in your Laravel project. What is the effect on API routes if you later add a new route in routes/api.php without clearing the cache?

A The new route will NOT be recognized until you clear and rebuild the route cache.

B The new route is automatically detected and works immediately.

C The application throws a syntax error on any new route added after caching.

D The new route is added but only accessible via web routes, not API.

💡 Hint

Route caching stores routes in a compiled file for speed but requires manual refresh after changes.

Route caching compiles all routes into a cache file. New routes added after caching are ignored until cache is cleared and rebuilt.