Form request classes in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What happens when a Laravel form request class fails validation?

Consider a Laravel form request class used in a controller method. What is the default behavior when the validation rules defined in the form request fail?

A The request is silently accepted without any validation.

B The controller method runs but with empty input data.

C The request is redirected back to the previous page with validation errors and old input data.

D The application throws a fatal error and stops execution.

💡 Hint

Think about user experience when submitting invalid form data.

Laravel automatically redirects back with errors and old input if validation fails in a form request class. This helps users correct their input easily.

📝 Syntax

intermediate

Which method must be defined in a Laravel form request class to specify validation rules?

In a Laravel form request class, which method is used to define the validation rules for the incoming request data?

A messages()

B validate()

C authorize()

D rules()

💡 Hint

This method returns an array of rules.

The rules() method returns an array of validation rules that Laravel applies to the request data.

❓ state_output

advanced

What is the value of $validated after calling validated() on a form request?

Given this Laravel form request class with rules:

public function rules() {
    return [
        'name' => 'required|string',
        'age' => 'nullable|integer|min:18'
    ];
}

And the incoming request data:

{"name": "Alice", "age": "20"}

What will $validated = $request->validated(); contain?

A {"name" => "Alice", "age" => 20}

B {"name" => "Alice", "age" => "20"}

C {"name" => "Alice"}

D An empty array

💡 Hint

Consider how Laravel casts validated input types.

The validated() method returns the validated data with types cast according to the rules. The string "20" is cast to integer 20.

🔧 Debug

advanced

Why does this Laravel form request always fail authorization?

Given this form request class snippet:

public function authorize()
{
    return false;
}

What is the effect of this code when used in a controller method?

A All requests using this form request will be denied with a 403 Forbidden response.

B The request will always pass authorization and proceed.

C The request will throw a validation error.

D The request will redirect back with an error message.

💡 Hint

Think about what returning false in authorize() means.

Returning false in the authorize() method denies all requests using this form request, causing Laravel to respond with HTTP 403 Forbidden.

🧠 Conceptual

expert

How does Laravel handle validation error messages in form request classes?

In Laravel form request classes, how can you customize the validation error messages for specific rules?

A By setting a public property $messages with the custom messages array.

B By defining a messages() method that returns an array mapping rules to custom messages.

C By overriding the rules() method to include messages inline.

D By editing the config/validation.php file only.

💡 Hint

Look for a method dedicated to messages in the form request class.

The messages() method in a form request class returns an array where keys are rule names and values are custom error messages.