# Mastering Hilt - Android | Kotlin | Hilt (Dagger 2) [Part 2]

### **Understanding Hilt Annotations**

* `@HiltAndroidApp`
    
* `@AndroidEntryPoint`
    
* `@HiltAndroidApp`
    

The `@HiltAndroidApp` annotation is used to mark the `Application` class as the entry point for Hilt in an Android application. This annotation enables Hilt to generate and manage the necessary components to enable dependency injection throughout the app.

Example:

```kotlin
@HiltAndroidApp
class MyApplication : Application() {
    // Application code
}
```

In this example, the `MyApplication` class is marked with `@HiltAndroidApp`, indicating that it serves as the entry point for Hilt. By applying this annotation, Hilt generates a `MyApplication_HiltComponents` class, which contains the necessary Dagger/Hilt components for the dependency injection.

**@AndroidEntryPoint**:

The `@AndroidEntryPoint` annotation is used to mark Android components (`Activities`, `Fragments`, `ViewModels`, etc.) as entry points for Hilt's dependency injection. This annotation allows Hilt to inject the required dependencies into these components automatically.

Example - Using `@AndroidEntryPoint` with an `Activity`:

```kotlin
@AndroidEntryPoint
class MainActivity : AppCompatActivity() {
    // Injected dependencies can be used here
    // ...
   
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        // ...
    }
}
```

In this example, the `MainActivity` class is marked with `@AndroidEntryPoint`. This annotation tells Hilt to generate code to inject the required dependencies into the `MainActivity` when it's created. Any dependencies that `MainActivity` needs, such as `ViewModel`, can be annotated with `@Inject`, and Hilt will automatically provide those dependencies.

Using `@AndroidEntryPoint` is essential to enable Hilt's automatic dependency injection in Android components, making the code cleaner and more maintainable by eliminating the need for manual dependency management.