Controller methods and actions in Laravel - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of a controller in Laravel?

A controller handles user requests, processes data, and returns responses. It acts like a middleman between the user and the application logic.

beginner

How do you define a method inside a Laravel controller?

A method is a public function inside a controller class that performs a specific action, like showing a page or saving data.

intermediate

What is the difference between a controller method and an action in Laravel?

In Laravel, a controller method is a function inside the controller class. An action usually refers to the method that handles a specific route or user request.

beginner

How do you link a route to a controller method in Laravel?

You define a route in routes/web.php or api.php and specify the controller and method using syntax like Route::get('/path', [ControllerName::class, 'methodName']).

intermediate

What is a resource controller in Laravel?

A resource controller is a controller with predefined methods for common actions like index, create, store, show, edit, update, and destroy. It helps organize CRUD operations easily.

Which keyword defines a method inside a Laravel controller?

A def

B var

C let

D public function

Laravel controller methods are defined as public functions inside the controller class.

How do you call a controller method named 'show' in a route?

A Route::get('/show', [Controller::class, 'show'])

B Route::show('/show')

C Route::get('/show', 'show')

D Route::controller('show')

You specify the controller class and method as an array in the route definition.

What does the 'index' method in a resource controller usually do?

A Show a form to create a new item

B List all items

C Update an item

D Delete an item

The 'index' method typically returns a list of all resources.

Which file usually contains the route definitions that link to controller methods?

A app/Http/Controllers

B config/app.php

C routes/web.php

D resources/views

Routes are defined in routes/web.php or routes/api.php files.

What is the main benefit of using resource controllers?

A They organize common CRUD methods in one controller

B They automatically generate views

C They replace routes completely

D They handle database migrations

Resource controllers group common CRUD actions into one controller for cleaner code.

Explain how a Laravel controller method handles a user request from route to response.

Think about the flow from URL to what the user sees.

Describe the purpose and typical methods included in a Laravel resource controller.

Focus on how resource controllers help manage common tasks.

Practice

1. What is the main purpose of a controller method (action) in Laravel?

easy

A. To handle a specific user request and return a response

B. To define database schema

C. To style the HTML output

D. To manage server configuration

Solution

1. Step 1: Understand controller role

   Controllers group related logic into methods called actions.

2. Step 2: Identify action purpose

   Each action handles a user request and returns a response like a view or JSON.

3. Final Answer:

   To handle a specific user request and return a response -> Option A

4. Quick Check:

   Controller action = handle request and respond [OK]

Hint: Controllers handle requests and responses, not styling or config [OK]

Common Mistakes:

• Confusing controller methods with database or styling tasks
• Thinking controllers manage server settings
• Assuming controllers only return views

2. Which of the following is the correct syntax to define a controller method named show in Laravel?

easy

A. function show() public { /* code */ }

B. public function show() { /* code */ }

C. public show function() { /* code */ }

D. def show() { /* code */ }

Solution

1. Step 1: Recall PHP method syntax

   In PHP, methods are defined with visibility, function keyword, name, and parentheses.

2. Step 2: Match Laravel controller method syntax

   Laravel uses PHP syntax: public function methodName() {}.

3. Final Answer:

   public function show() { /* code */ } -> Option B

4. Quick Check:

   PHP method = public function name() [OK]

Hint: Remember PHP method syntax: visibility + function + name() [OK]

Common Mistakes:

• Placing visibility after function keyword
• Using Python style def keyword
• Omitting parentheses after method name

3. Given this controller method in Laravel:

public function greet($name) {
    return "Hello, " . $name . "!";
}

What will be the output if called with $controller->greet('Anna')?

medium

A. "Hello, Anna!"

B. "Hello, $name!"

C. Error: Undefined variable

D. "Hello, !"

Solution

1. Step 1: Understand method parameter usage

   The method receives $name and concatenates it with strings.

2. Step 2: Substitute argument value

   Calling with 'Anna' replaces $name with 'Anna', so output is "Hello, Anna!".

3. Final Answer:

   "Hello, Anna!" -> Option A

4. Quick Check:

   Parameter value used in string = "Hello, Anna!" [OK]

Hint: Replace parameter with argument value to find output [OK]

Common Mistakes:

• Treating $name as literal string
• Expecting error due to missing variable
• Ignoring string concatenation

4. Identify the error in this Laravel controller method:

public function index()
{
    return view('welcome')
}

medium

A. View name should be capitalized

B. Incorrect method name

C. Missing semicolon after return statement

D. Missing parentheses in view() call

Solution

1. Step 1: Check PHP syntax in method

   PHP statements must end with a semicolon; here it is missing after return view('welcome').

2. Step 2: Validate other parts

   Method name and view call syntax are correct; view name case is not an error.

3. Final Answer:

   Missing semicolon after return statement -> Option C

4. Quick Check:

   PHP statements end with ; [OK]

Hint: Check for missing semicolons after return statements [OK]

Common Mistakes:

• Ignoring missing semicolon causing syntax error
• Thinking view names must be capitalized
• Assuming parentheses are missing in view()

5. You want to create a Laravel controller method that returns a JSON response with a user's name and email. Which method correctly does this?

public function userInfo()
{
    $user = ['name' => 'John', 'email' => '[e-mail]'];
    // Fill in the return statement
}

hard

A. return json($user);

B. return json_response($user);

C. return response->json($user);

D. return response()->json($user);

Solution

1. Step 1: Recall Laravel JSON response syntax

   Laravel uses response()->json() helper to return JSON responses.

2. Step 2: Check each option's syntax

   return response()->json($user); correctly calls response()->json($user);. Others are invalid or incorrect syntax.

3. Final Answer:

   return response()->json($user); -> Option D

4. Quick Check:

   Use response()->json() for JSON output [OK]

Hint: Use response()->json() helper to return JSON [OK]

Common Mistakes:

• Using undefined functions like json() or json_response()
• Missing parentheses or arrow operator in response call
• Confusing PHP syntax for method calls