Dependency injection with Hilt in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Dependency Injection (DI) in Android development?

Dependency Injection is a way to provide objects that a class needs (its dependencies) from outside, instead of creating them inside the class. It helps make code easier to test and maintain.

beginner

What is Hilt in Android development?

Hilt is a library built on top of Dagger that simplifies dependency injection in Android apps. It provides standard components and annotations to reduce boilerplate code.

beginner

What annotation do you use to tell Hilt to provide a class as a dependency?

You use the @Inject annotation on the constructor of the class you want Hilt to provide as a dependency.

intermediate

How do you make an Android Activity ready for Hilt injection?

You add the @AndroidEntryPoint annotation to the Activity class. This tells Hilt to generate the necessary code to inject dependencies into that Activity.

intermediate

What is a Hilt Module and why do you need it?

A Hilt Module is a class annotated with @Module and @InstallIn that tells Hilt how to provide dependencies that you cannot annotate with @Inject, like interfaces or third-party classes.

Which annotation marks a class constructor for Hilt to provide its instances?

A @Provides

B @Module

C @Inject

D @AndroidEntryPoint

The @Inject annotation on a constructor tells Hilt how to create instances of that class.

What annotation do you use on an Android Activity to enable Hilt injection?

A @AndroidEntryPoint

B @Inject

C @Module

D @Singleton

The @AndroidEntryPoint annotation is used on Activities, Fragments, and other Android classes to enable Hilt injection.

If you want to provide a third-party library instance with Hilt, what should you create?

A An @Inject constructor in the library

B An @AndroidEntryPoint annotation

C A @Singleton annotation on the library

D A Hilt Module with @Provides functions

You create a Hilt Module with @Provides functions to tell Hilt how to provide instances of classes you cannot modify.

What scope annotation would you use to make a dependency live as long as the application?

A @ActivityScoped

B @Singleton

C @FragmentScoped

D @Reusable

The @Singleton annotation makes the dependency live as long as the application.

Which Hilt annotation specifies where a Module should be installed?

A @InstallIn

B @Module

C @Provides

D @EntryPoint

The @InstallIn annotation tells Hilt which component the Module belongs to, like SingletonComponent or ActivityComponent.

Explain how Hilt simplifies dependency injection in an Android app.

Think about how Hilt manages dependencies and Android classes with simple annotations.

Describe the steps to inject a dependency into an Android Activity using Hilt.

Focus on annotations and how Hilt connects dependencies to Android components.