Android Interview Question Answer: MVVM Pattern Explained

Continue your Android interview preparation with Part 2 of our series! Covering advanced concepts, best practices, and real-world Android development interview questions. Read Part 1 here link on LiveData, and ViewModel

MVVM

1. What is the MVVM architecture pattern and why is it used in Android development.

MVVM stands for Model View ViewModel. It is an architecture design used in Android development to structure the code and separate the UI views and data model to easily test and maintain the code. This helps improve the separation of concerns and testability of the application.

2. Explain the roles of Model, View, and ViewModel in MVVM.

ViewModel: It will act as a mediator between the data layer and the UI layer

View: Display the data to the user receive user action and send it to the viewModel.

Model: Represent the data of the application and data processing.

3. Difference between MVP, MVVM, and MVC patterns?

In MVP, the Presenter handles user input and updates the View,

In MVVM, the ViewModel automatically updates the View via data binding or provided observer or LiveData.

In MVC, the Controller directly manipulates the View without a middleman like the Presenter

4. What is the role of the Repository in MVVM architecture?

The Repository plays a crucial role in the MVVM it serves as a centralized point for managing and accessing data. So all the data that is coming through API and saved to the local database is passed through this layer.

5. Explain How data are flowing in the MVVM pattern.

Data are flowing in MVVM in a structured way ensuring separation of concern and each component is doing their job to complete the assigned task.

Below are the Steps on how it happens,

· First there will be user interaction on the screen or any event that fires up from the UI.

· Based on the User Action UI will send an event or trigger the data binding to call the ViewModel method.

· ViewModel processes the user input and performs any necessary business logic. It may also interact with the Repository to fetch or update data.