Can you give an example illustrating the Single Responsibility Principle in SOLID principles?

The Single Responsibility Principle (SRP) states that a class should have only one reason to change, meaning it should be responsible for a single specific task.

Example in Android: suppose you have a class UserManager that is responsible for both fetching user data from the network and saving that data to a database.

This violates SRP because the class is responsible for two different tasks — network interaction and database operations.

A better approach is to separate these responsibilities:

class UserNetworkService {
    fun fetchUserData(userId: String): User {
        // code to fetch data from network
    }
}

class UserRepository {
    fun saveUser(user: User) {
        // code to save user to database
    }
}

class UserManager(
    private val networkService: UserNetworkService,
    private val repository: UserRepository
) {
    fun updateUser(userId: String) {
        val user = networkService.fetchUserData(userId)
        repository.saveUser(user)
    }
}

This approach simplifies maintenance and testing, as each part is responsible for its own area of concern.