Angular Web Framework Services & Dependency Injection

Question 1

What is a service in Angular?

Accepted Answer

A class with a focused purpose that provides shared functionality across components

Answer

A background process that runs on the server

Answer

An HTML element for displaying content

Answer

A CSS animation keyframe

Question 2

What is dependency injection (DI) in Angular?

Accepted Answer

A design pattern where dependencies are provided to a class rather than created by it

Answer

A method for injecting malicious code into applications

Answer

A database query optimization technique

Answer

A CSS injection for dynamic styling

Question 3

What does 'providedIn: root' mean in an @Injectable() decorator?

Accepted Answer

The service is available application-wide as a singleton through the root injector

Answer

The service is only available in the root component

Answer

The service requires root/admin permissions

Answer

The service stores data in the root directory

Question 4

What is the purpose of HttpClient in Angular?

Accepted Answer

To make HTTP requests to APIs and external services

Answer

To create HTML client-side templates

Answer

To manage client-side routing

Answer

To handle WebSocket connections only

Question 5

What is an interceptor in Angular?

Accepted Answer

A service that intercepts and optionally modifies HTTP requests or responses globally

Answer

A debugging tool that intercepts console logs

Answer

A routing guard that intercepts navigation

Answer

An error handler that intercepts all exceptions

Question 6

What is the difference between a service and a component in Angular?

Accepted Answer

Components manage UI and views; services contain reusable business logic and data access

Answer

There is no difference

Answer

Services render HTML; components do not

Answer

Components are only used on the server side