Android interview questions for experienced candidates

 


          Hi, I am Rajesh Bhatt, I have mentored many developers, and their efforts landed  them high-paying tech jobs. I am passionate about sharing  My knowledge .

            

Android :

1- When I am in my activity get a phone call what will be the lifecycle of the activity

2- When I am in my activity get a phone call what will be the lifecycle of the fragment inside my activity

3-Fragment, activity and application life cycle and when there life cycle method get trigger.

4-Difference between fragment or activity

5- What is fragment.

6- What happen when we press back button on activity A.

7- Which activity life cycle method trigger when orientation change.

8- When onDistroy will get called before onPause or onStop.

9- Type of services in Android

10- What do you think about NavHost in navigation

11- What are SOLID principles?

12- What is broadcast receiver and content provider and how can we implement it.

13- Advantage of using recycle view over list and grid view.

14- Launch mode and there type and differences.

15- Data binding and its type.

16- How to pass data from activity to fragment or fragment to fragment.

17- Difference between adding or replacing a fragment.

18- What is Intent and its typ.

19- Constraint layout and its advantage.

20- Difference between push value and set value ( Live Data ).

21- Advantage of using live data.

22- What is Dex file.

23- Which database you use and why.

24- Benefit of using Room database.

25- Difference between room and sqlite.

26- Difference between service and thread.

27- What's is concurrency.

28- How to improve app performance.

29- What is memory leak and how to avoid it.

30- How to go back on previous fragment when click on back button.

31- How to communicate between service and activity.

32- What is concurrency.

33- On which thread service run and how can we change the thread.

34- Job intent service and its purpose.

35- How to improve application performance.

36- What is memory leak and how to solve it.

37- How service will communicate with activity.

38- What is job scheduler and its work.

39- Parameter constructer and non parameter constructer are good and why in fragment.

Kotlin :

1- What are the benefits of Kotlin over Java.

2- Explain the use of lateinit & lazy keywords.

3- How to check lateinit class is initialize or not.

4- What is null safety in Kotlin?.

5- What is the diff between Var & Val and const and val.

6- What is Elvis operator.

7- What is Flow API in Kotlin.

8- Explain coroutines in kotlin.

9- What are scoped functions and there use in kotlin.

10- What is singleton class and how can you declare it.

11- What is the diff between companion obj & object.

12- Used extension functions? example.

13- Data class and how its different from other classes.

14- What is Sealed class.

15- What is suspend function.

16- What is the diff between static & singleton Explain @jvmstatic @jvmoverloads @jvmfiled.

17- Difference between volatile and syncronized.

18- Live data, Mutable live data and Mediator live data
Advantage of live data.

19- What is flow , state flow and shared flow.

20- Extension, inline, inflix and high order function and there benefit in term of memory.

21- Difference between public ( visiblity modifier ) and open keyword.

22- Difference between volatile and synchronized.

23- Arraymap and hashmap.

24- How hashmap work in background.

25- What is referential equality and structal equality.

26- Will reference of two data class with same set of data will it be equal or not.

Java :

1- What is the diff between encapsulation & abstraction give practical example.

2- Explain OOP Concepts.

3- Will reference of two data class with same set of data will it be equal or not.

4- When to use array & Array List.

5- What is the volatile keyword.

6- What is the transient keyword.

7- What is a diff between a string buffer & string builder.

8- Why is string immutable.

9- What is the diff between encapsulation & abstraction (practical example).

10- 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.

11- What is the difference between String test = new String(“X”) & String test = “X”. Explain String constant pool & String literal.


Kotlin Coroutines :

1- What is coroutines.

2- What is coroutines dispatchers there type and work.

3- What is coroutines scope and its type.

4- What is coroutines context.

5- What is coroutines builder, its type and there work.

6- Difference between launch and async.


ViewModel:

1- What is ViewModel and its advantage.

2- How to instantiate viewmodel.

3- What is the difference between ViewModel and AndroidViewModel.

4- How ViewModel work internally.

5- How ViewModel retain data during configuration change.

6- During configuration change activity distroy and re-create then how view-model instance remain same.

7- What is view-model factory & how to pass data in view model constructor.

8- Difference between shared view model and view model.


Dependency Injection:

1- What is Dependency Injection and its benefit.

2- Where should we write code of DI.

3- How hilt provide required object should we write it.



Mvvm :


1- What is MVVM, and how does it work and its advantage.

2- What is the diff between MVP/MVC & MVVM.



Networking libraries ( Retrofit & Volley ):

1- Which one you prefer to use and why?

2- advantage of using retrofit.



Rajeshbhatt12

My name is Rajesh Bhatt. I am working as a senior android developer . I have created this blog for kotlin ,java and Android Development interview questions etc..

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