Most Asked Android Interview Questions In 2022

Most Asked Android Interview Questions In 2022 - Your Guide For Android Interview Preparation

Prepared and maintained by Rahnuma Sharib who is having experience of taking interviews of many Android developers.

Hi, I am Rahnuma Sharib, I have mentored many developers, and their efforts landed them high-paying tech jobs. I am passionate about sharing knowledge through open-source, blogs, and videos.

Android

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

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

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

• Difference between fragment or activity

• What is fragment.

• What happen when we press back button on activity A.

• Which activity life cycle method trigger when orientation change.

• When onDistroy will get called before onPause or onStop.

• Type of services in Android

• What do you think about NavHost in navigation

• What are SOLID principles?

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

• Advantage of using recycle view over list and grid view.

• Launch mode and there type and differences.

• Data binding and its type.

• How to pass data from activity to fragment or fragment to fragment.

• Difference between adding or replacing a fragment.

• What is Intent and its type

• Constraint layout and its advantage

• Difference between push value and set value ( Live Data )

• Advantage of using live data

• What is Dex file.

• Which database you use and why

• Benefit of using Room database

• Difference between room and sqlite.

• Difference between service and thread.

• What's is concurrency.

• How to improve app performance.

• What is memory leak and how to avoid it.

• How to go back on previous fragment when click on back button.

• How to communicate between service and activity.

• What is concurrency.

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

• Job intent service and its purpose

• How to improve application performance.

• What is memory leak and how to solve it.

• How service will communicate with activity.

• What is job scheduler and its work.

• Parameter constructer and non parameter constructer are good and why in fragment.

Kotlin

• What are the benefits of Kotlin over Java

• Explain the use of lateinit & lazy keywords

• How to check lateinit class is initialize or not.

• What is null safety in Kotlin?

• What is the diff between Var & Val and const and val

• What is Elvis operator?

• What is Flow API in Kotlin

• Explain coroutines in kotlin

• What are scoped functions and there use in kotlin

• What is singleton class and how can you declare it?

• what is the diff between companion obj & object

• Used extension functions? example

• Data class and how its different from other classes.

• Sealed class.

• What is suspend function.

• what is the diff between static & singleton Explain @jvmstatic @jvmoverloads @jvmfiled

• Difference between volatile and syncronized.

• Live data, Mutable live data and Mediator live data

• Advantage of live data

• What is flow , state flow and shared flow

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

• Difference between public ( visiblity modifier ) and open keyword

• Difference between volatile and synchronized.

• Arraymap and hashmap.

• How hashmap work in background.

• What is referential equality and structal equality.

• Will reference of two data class with same set of data will it be equal or not?

Java

• What is the diff between encapsulation & abstraction give practical example

• Explain OOP Concepts.

• Will reference of two data class with same set of data will it be equal or not?

• When to use array & Array List

• What is the volatile keyword

• What is the transient keyword

• What is a diff between a string buffer & string builder

• Why is string immutable

• What is the diff between encapsulation & abstraction (practical example)

• 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

Kotlin Coroutines.

• What is coroutines.

• What is coroutines dispatchers there type and work.

• What is coroutines scope and its type.

• What is coroutines context.

• What is coroutines builder, its type and there work.

• Difference between launch and async.

ViewModel.

• What is ViewModel and its advantage.

• How to instantiate viewmodel.

• What is the difference between ViewModel and AndroidViewModel.

• How ViewModel work internally.

• How ViewModel retain data during configuration change.

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

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

• Difference between shared view model and view model.

Dependency Injection.

• What is Dependency Injection and its benefit.

• Where should we write code of DI.

• How hilt provide required object should we write it.

Mvvm

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

• what is the diff between MVP/MVC & MVVM

Networking libraries ( Retrofit & Volley )

• Which one you prefer to use and why?

• advantage of using retrofit.

VCS ( Git)

• what is Marge and rebase in git.

• how you create branch and work on them .

Jetpack Compose

• What are the benefits of using Jetpack compose?

• What is a Composable function?

• What is a declarative approach?

• What jetpack compose libraries have you used?

• Explain compose UI basic components

Testing

• In Unit testing, what is @Before & @Beforeclass annotation used for

• Why should we use a Mockito lib?

• Explain Unit & Instrumentation tests

Data Structure

• What is Queue, Stack and Array.

• The time complexity of Hash Table — O(1).

• Best for getting the last item — Stack

• Time Complexity of Binary Search — O(log N)

• Which is best Sorting Algo — Quick Sort

• Best performance for finding minimum value — Array

That’s a wrap for now! Many more to come I hope you find this blog helpful.

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