Question 1

What is dependency injection and what are the main benefits of applying it in Android?

Accepted Answer

It is a design pattern that dictates passing the dependencies an object needs from outside instead of the object creating them itself inside its constructor.

Question 2

What is Hilt and what advantages does it offer over the Dagger 2 library for Android apps?

Accepted Answer

Hilt is an official library built on top of Dagger to simplify its use on Android by providing predefined standard components for screen lifecycles and removing the need to write complex boilerplate code by hand.

Question 3

What is the role of the basic annotations in Hilt: @HiltAndroidApp, @AndroidEntryPoint, and @Inject?

Accepted Answer

@HiltAndroidApp creates the root container, @AndroidEntryPoint prepares Android components for dependency injection, and @Inject requests the dependency or defines how to create it.

Question 4

What is the difference between @Provides and @Binds inside Module classes in Hilt?

Accepted Answer

@Binds is a quick abstract function for binding an interface to its direct implementation; @Provides is a regular function used when building the object requires logic or when the object comes from an external library.

Question 5

How does the component hierarchy and lifecycle scopes work in Hilt?

Accepted Answer

Scopes tie dependency objects to the lifecycle of specific Android components: @Singleton for the whole app, @ActivityScoped for the activity, and @ViewModelScoped for the ViewModel's lifecycle.

Question 6

How do you resolve the conflict of providing two different instances of the same type using qualifiers in Hilt?

Accepted Answer

By defining custom annotations marked with @Qualifier to distinguish each instance (such as an authenticated network client and a public network client).