Basic Internal Working of Hilt Dependency Injection in Android: Key Concepts Explained

Dependency Injection (DI) is a crucial concept in modern Android development, enabling better code maintainability, scalability, and testability. Hilt, built on top of Dagger, is the official dependency injection framework recommended by Google for Android. In this blog, we’ll dive deep into the internal workings of Hilt, exploring how it simplifies dependency injection, how it operates behind the scenes, and why it’s essential for building robust Android applications.

What is Dependency Injection?

Dependency Injection is a design pattern where an object’s dependencies are provided externally rather than the object creating them itself. This decouples object creation and object usage, making the code easier to test and manage.

Example without DI

class Engine {
    fun start() = "Engine started"
}

class Car {
    private val engine = Engine()
    fun drive() = engine.start()
}

Example with DI

class Car(private val engine: Engine) {
    fun drive() = engine.start()
}

Here, Engine is injected into Car, increasing flexibility and making it easier to swap or mock dependencies.

Why Hilt for Dependency…