Junior android developer interview questions

Below is a list of questions I asked in an interview for a junior developer. The concept of "Junior Developer" differs from company to company and even from project to project, therefore these questions may seem very complex to you, or vice versa, very simple for this position.

Each question has links to articles that contain the answer to the question and could be given to the developer if he/she is not answered the related question.

If you don't agree with this list or have suggestions on what to change/add to it, we can always discuss in the Discussions.

If you have a list of questions for a junior android developer that you want to share, please create a pull request, it's always welcome.

General

1. What OOP principles do you know?

• Lesson: Object-Oriented Programming Concepts
• Polymorphism, Encapsulation, Data Abstraction and Inheritance in Object-Oriented Programming
• OOPs in Java: Encapsulation, Inheritance, Polymorphism, Abstraction

Java

2. What is the difference between overriding and overloading?

• Overriding vs Overloading in Java
• What is the difference between Method Overloading And Overriding?

3. What do you know about interface keyword?

• Java Interfaces
• Java Interfaces
• Interface (Java)

4. What do you know about try-catch-finally?

• Basic try-catch-finally Exception Handling in Java
• Java try catch finally Blocks
• Flow control in try catch finally in Java

5. What are the basic interfaces of Java Collections Framework?

• Java Collections
• Java collections framework
• Introduction to Java Collections

6. What is the difference between ArrayList and LinkedList?

• Java ArrayList vs LinkedList
• Difference Between ArrayList and LinkedList in Java - Code and Performance

7. Describe how HashMap works

• Internal Working of Java HashMap
• Working of HashMap in Java
• Internal Working of HashMap in Java

Kotlin

8. What do you know about data classes?

• Data classes
• Kotlin Data Class

9. What do you know about sealed classes?

• Sealed classes and interfaces
• Sealed with a class
• Sealed Classes in Kotlin

10. Describe visibility modifiers

• Visibility modifiers
• Kotlin for Android Developers: Visibility Modifiers

11. What's Companion Objects?

• Kotlin Companion Object
• A few facts about Companion objects

12. What do you know about extensions?

• Extensions
• Extension Functions in Kotlin

13. What is the difference between lazy and lateinit?

• Property initialization using "by lazy" vs. "lateinit"
• lateinit vs lazy Property in Kotlin

14. What are coroutines?

• Coroutines basics

Android

15. What is Activity?

• Introduction to activities
• Activity

16. What is Fragment?

• Fragments
• Building dynamic user interfaces in Android with fragments - Tutorial

17. What is View?

• View
• The Life Cycle of a View in Android

18. What is RecyclerView?

• Android RecyclerView Tutorial in Kotlin
• Android RecyclerView Tutorial with Kotlin

19. What is Jetpack Compose?

• Build better apps faster with Jetpack Compose

20. What is ViewModel?

• ViewModel overview
• ViewModels : A Simple Example

21. What is LiveData?

• LiveData overview
• Understanding LiveData made simple

22. How to support different screen size in android?

• Support different screen sizes

Git

23. What is the difference between git rebase and git merge?

• Git Rebase vs. Merge: A Complete Guide
• Merging vs. Rebasing