Services

What best describes a service in backend development?. A module that directly handles client requests and sends responses. A component that contains the business logic and provides reusable functionality to other parts of the system. A database system that stores all the data of the application.

Which of the following statements is NOT true about a backend service?. It focuses on implementing business logic rather than managing HTTP requests. It is tightly coupled with the database structure. It can be reused by multiple controllers or components.

What is the main purpose of using a service layer in backend architecture?. To store user data efficiently. To separate business logic from controllers and data access layers. To define the routes and endpoints for API calls.

In a typical backend project, who usually calls the services?. The database directly. Controllers or other services. The front-end client.

Which of the following best illustrates a service in an e-commerce application?. A class that handles HTTP routes for product endpoints. A class that calculates the total price and applies discounts. A class that renders the shopping cart page.

Why are services considered a key component in backend architecture?. They centralize the logic, making it easier to test, maintain, and reuse. They mainly serve as intermediaries between frontend and backend. They are used only for connecting to databases.

Which of the following elements is usually part of a service’s structure?. Route definitions and HTTP methods. Business logic and calls to repositories or external APIs. HTML templates for rendering pages.

What is the main internal component of a service?. The business logic methods that define what actions the application performs. The user interface components. The configuration files for the server.

In a typical service, which component is responsible for communicating with the database?. The repository layer or data access object (DAO). The service itself. The controller.

Which of the following correctly represents the typical structure of a service file in a backend project?. Import dependencies → Define class/functions → Export → Use in controller. Create routes → Define middleware → Send response. Connect to database → Execute SQL → Return result.

What part of a service helps it stay modular and reusable?. It directly modifies shared global variables. It defines clear, independent methods for each operation. It mixes business logic with routing logic.

In frameworks like NestJS or Spring Boot, services are often implemented as: Plain text files that store configuration values. Classes decorated or marked as injectable components. HTML templates that handle user interfaces.

Which of the following best describes the responsibility boundaries of a service?. It should handle both HTTP requests and database connections directly. It should focus only on business logic, delegating HTTP and database concerns elsewhere. It should handle front-end rendering for user interfaces.

When implementing a service, what is the first typical step?. Creating the database schema. Importing required dependencies or interfaces the service needs. Writing the controller routes.

What is the most common structure when implementing a service in many backend frameworks?. A class or object containing methods that represent business operations. A file full of global functions without organization. A file that returns HTML directly.

In service implementation, how do you usually receive external dependencies (repositories, helpers, etc.)?. By embedding the code directly inside the service. By using Dependency Injection or constructor parameters. By hardcoding all the dependencies into global variables.

What is a best practice when implementing service methods?. Each method should perform one clear business action. Each method should handle multiple unrelated operations to reduce files. Each method should directly send HTTP responses.

When implementing a service, where should error handling usually occur?. Inside the service methods, throwing controlled errors or returning meaningful exceptions. Only inside the controller. Only inside the database layer.

Which of the following is a correct step when implementing a service method that needs data from the database?. Access the database directly using SQL queries inside the service. Call the repository or DAO, which handles all database operations. Make the service connect to the database on every request.

When exporting a service so it can be used in controllers or other services, what is the typical approach?. Export the class or instance from the service file. Copy and paste the entire service code into the controller. Declare the service as a global variable in the application.