Android Interview Question Bank 🏦

Hey Android Devs 💚,
I am working as a full-time Android Developer for a long time now in a client-based IT company. And during my service, I am fortunate enough to appear in a few client interviews for MNCs & startups as well. My intent to write this blog is to share my past interview experiences & help you all out with your journey.

I habitually note down questions immediately after completing my interview round. I have listed down below some interview questions for senior developers and tried to include answers to most questions as well.

I have also attached the Codelab link to try coding examples & Quiz links for the MCQ round at the end of this blog. Also, I have added a publication link to learn jetpack Compose from scratch with example code as it’s a hot skill nowadays!

Java ☕️

• What is the diff between encapsulation & abstraction (practical example) — Check here
• HashMaps vs HashTables — Check here
• When to use array & ArrayList — Check here
• What is the volatile keyword — Check here
• What is the transient keyword — Check here
• What is a diff between a string buffer & string builder — Check here
• Why is string immutable — Check here
• Explain multithreading. How two threads pass messages internally — Handler
• class A -> extends class B, implements interface C. Both have the same method fun add() {}, Which one will be implemented in class A?
  Try yourself
• What is the difference between String test = new String(“X”) & String test = “X”. Explain String constant pool & String literal — Check here

Android

• When I am in my activity onResume() & get a phone call what will be the lifecycle of the fragment inside my activity — Try yourself
• Explain context & applicationContext, also a practical example — Check here
• what is the difference between ViewModel and AndroidViewModel — Check here
• what is the diff between MVP & MVVM — Check here
• Tell me any method of broadcast receiver except onReceive() — Check here
• How Broadcast receiver is used for the network (WIFI) changes — Check here
• Type of services in Android — Check here
• Is the Intent service run on background or main thread — Check here
• Explain FCM foreground & background notifications — Check here
• Design patterns in Android — Check here
• What do you think about NavHost in navigation? — Check here
• Explain database management using SQLite, Room & Realm — Check here
• What is a foreign key in Room DB? Why do we use it? — Check here
• What is doze mode, and when is it introduced? — Check here
• what is ADB, can you tell me any commands? — Cheatsheet
• what is linting in Android — Check here
• What is Rxjava, and how it works? — Check here
• What are SOLID principles? — Check here
• Have you worked with any other hardware systems? (i.e. I have worked with Clover POS system)
• What is KMM? — Check here

Kotlin

• What are the benefits of Kotlin over Java
• Explain the use of lateinit & lazy keywords
• In any class we have a member variable or function, so how can we make a getter setter of that variable?
• What is MVVM, and how does it work? what is the use of Live data?
• What is null safety in Kotlin?
• What is the diff between Var & Val
• What is Elvis operator?
• What is Flow API in Kotlin — Check here
• Explain coroutines in kotlin
• What are scoped functions in kotlin
• How can you declare a singleton class
• what is the diff between companion obj & object
• used extension functions? example
• what is the diff between static & singleton > Singleton has an instance/object while static class is a bunch of static methods.
• what is constant
• Explain @jvmstatic @jvmoverloads @jvmfiled

You can get most of the Kotlin answers here:
https://blog.mindorks.com/kotlin-android-interview-questions

This article was originally published on proandroiddev.com on October 14, 2022