Your Cheat Sheet For Android Interview - Android Interview Questions.
Tags: android, kotlin, java, oops
Published: 2021-11-22 19:18:29

**_Most Commonly Asked Android Interview Question for Android Developer._**

**OOPS CONCEPT**

1. What are basic components of OOPS?.
2. What is Object?.
3. What will happen if we do not follow up OOPS concepts in  software development.
4. Difference between Abstraction and Data encapsulation?.
5. How abstraction and encapsulation can be archived.
6. What is Polymorphism? Give Example.
7. How to perform Polymorphism in Android?. How polymorphism is relevant in android. Use case?
8. What are Compile time polymorphism and run time polymorphism?. With Example Code
9. What is method Overloading and method Overriding?
10. What is Interface? 
11. What is the use of interface. What's it's importance in OOPS concepts
12. Can we use methods and body inside interface?
13. What is default keyword do in interface?
14. What is abstract keyword?
15. Can methods allowed in abstract class. Explain an example of abstract class 
16. What is constructor.? what is the use of it
17. What is loose coupling and tight coupling in OOPS
18. Difference between new and override keyword



**Recommended: Please solve it first, before moving on to the solution.**

**_JAVA RELATED QUESTIONS_**
1. What type of Programming language is Java?
2. What is Method in Java?
3. What is base class of every java class
4. What are data types available in Java?
5. How to Assign double to int in java
6. What are access modifiers in java available? Explain each of them.
7. What does public **static void main** keyword do in Java ?
8. What is the use of static keyword in Java?
9. What is this  and super keyword?
10. What is the use of new keyword?
11. What is constructor in java? What is the need of it.
12. Different between base class and super class in Oops 
13. What is enum classes?.
14. What is difference between enum classes and constant classes
15. What is Singleton?
16. What is Difference between singleton and static?
17. How to hide a method in java.
18. What are Exception class in Java.
19. What are static and final class in java.
20. How to call static in java?
21. What is collection Framework? what does it do.
22. Give some of names of Exception class available in java.
23. What is difference between final, finally, and finalize keyword in Java?
24. Give an example of try and catch block statement?
25. Can we perform try without catch block statement? Give an example.
26. What are null pointer Exception in java?
27. What is interface?
28. Can we Instantiate abstract class?
29. What is Default Interface
30. What are methods we can use in interface?
31. Why to use interface over abstract class?
32  What is abstract class?
33. What is the difference between interface and abstract class? Give an example
34. What is Map?
35. How does Hash Map works?
36. Difference between Array List Vs Linked List?
37. Difference between Hash Map and Hash Set?
38. Difference between Hash-map and Hash Table?
39. What is asynchronous programming
40. What is Concurrency in java?
41 What is Thread in Java? How to created a thread?
42. Can java method overloading contains two same method name and signature allowed?

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**ANDROID QUESTION**

1. What is Android?
2. What are Android App Components ?
3. What is Android Manifest?
4. Why we use Exported true in Android Manifest? 
5. Difference between Activity and Fragment .
6. Can we created activity without layout?
7. What is Fragment? How does it works? 
8. What is Services With Example and Implementation?
9. What are types of Services?
10. What is Thread? What is the use of Thread? what are lifecycle of thread?
11. Which one is better Service or Thread?
12. What are API available for Services?
13. How do we interact UI With Services?
14. What is Lifecycle of an Activity ?
15. What is Lifecycle of an Fragment ?
16. What are alternative of threading in Kotlin?
17. What is broadcast Receivers With Example and Implementation?
18. What is the use of Local Broadcast receiver
19. What is Intent Filter ?
20. How to start an intent?
21. What are the different types if launch mode? Explain them each
22. What are Content Provider? How to use them?
23. What is Local Broadcast receivers?
24. What is Android Architecture Components ?
25. What is boot sequence of android
26. What is Dozy in Android ?
27. What are different types Android Architecture ?
28. What is MVVM, Why to use it?
29. What is Application Class in Android
30. What is Application level gradle and Android level gradle?
31. What are different types of Intents in Android
32. What is Hash-map with Implementation
33. What is Hash-table with Implementation
34. What is Arrays,  Array-list, Linked-list with example ?
35. What are different types of data structure (Difference between Linear and Non Linear DS)
36. What is savedInstanceState in Android?
37. What is Bundle in Android?
38. How to pass Data from one Activity to Another Activity ?
39. How to implement Fragment ?
40. What is Main difference between .apply and .commit in fragment ?
41. What is APK?
42. Different Layout Inflation Method  in Android
43. How does Vie Model Work passing data to View?
44. What are different Storage Option we Have in Android
45. How to Perform Room Database in Android
46. Why, When and How to Use Shared Preferences ?
47. How to build Own Notification Class.
48. What is difference between Handler, Looper and Thread
49. What are Different types of services we have in android
50. What is MVI, MVP. and how does it can br implemented
51. What is Dagger. Why to used, how to use
52. What is boilerplate code
53. What is difference between hilt and DI dagger?
54. How to pass constructor of a class without using dagger hilt
55. What is content provider? How to use content provider?
56. How to use andoid core location feature? Details about masks 
57. Can android manifest have two launcher intent filter?
58. What is AsyncTask? What are alternative of async task? In modern android development?
59. Difference Recycler view Vs ListView
60. What is difference between Activity and 
    AppCompactActivity
61. WorkManager ,JobScheduler ,JobDispatcher ,AlarmManager, BroadcastReceiver.
62. Working of Runnable, Handler and Looper. How Android thread is different from Java Thread ? Explain handler threads.
63. Concurrency framework in Android and their usecases .
64. What are the problems in AsyncTask ? What is the relationship between the lifecycle of an AsyncTask and an Activity ? What problems can this result in ?
65. Describe the working of different methods of RecyclerView.
66. When to Register/Unregister Broadcast Receivers created in an activity? Advantage of preferring onStart()/onStop() and onResume()/onPause() over onCreate()/onDestroy().
67. What is the difference between ListView and RecyclerView ?
68. Given 50 items and maximum visible rows, find how many times onCreateViewHolder will be called .
69. How would you communicate between two fragments ?
What are weak references and Strong references (along with examples) ?
70. Causes of memory leaks in Android applications ?
71. What is SparseArray ?
72. What is difference between Serializable and Parcelable ? Which is better in Android and why ?
73. What is AIDL.
74. What is FrameLayout?
75. What are android components? 
76. What is AppCompactActivity
77. Can activity be replaced without UI?
78. What is lifecycle of activity?
79. What is lifecycle of fragment?
80. What is lifecycle of thread?
81. What is lifecycle of ViewModel?
82. What are types of Services? How to write a service class
83. What are launchModes in Android? How Does it Work. Demo
84. What are storage option available in android
85. What are implicit and Explicit intent.
86. What is boot sequence in android?
87. How do you interact activity with services?
88. What are methods came in activity.
89. How to create a Json  object to Json Array in java
90. How to test android builds
91. What is the use of asynchronus programming?
92. How to write custom exception class in android?
93.How to test before application goes live in android?
94. How Does room database work
95. What is the internal Working of SQLite 
96. What are POJO class in android?
97. What are access modifiers in java
98. What are data types available in java
99. Explain Android Architecture 
100. How Does RecyclerView Work in android how does it maintain it's set on click listener of different items?
101. How to set Priority of Thread?
102. When to use activity and when to use services?
103. Some Libraries you have worked on in android? can refer below
104. How to pass List of Images from Activity A to Activity B?
105. How does MVI Works? give an achitecture
106. How to write ExceptionClass? How to Handle them?
107. Usage of try and catch block in java.
108. How to send data from oen activity to another activity and received application as notepad application.
109. What is .databaseBuilder() in Room database?
110. What is ThreadPool?
91. What are dependency required for MVVM?
96. How does MVVM Work? What is use of observer there?
103. What is Live Data? why to use it? when to use it.
104. How does firebase messaging payload works(messaging)
105. What is serializable and Parceble? How does it works
106. What is data binding? What is syntatic in kotlin
34. How to reduce APK size in android


**Recommended: Please solve it first, before moving on to the solution.**


**KOTLIN RELATED QUESTIONS**

1. Why to choose Kotlin as android development?
1. What are disadvantage of kotlin
2. What is difference feature we have in Kotlin what was missing in Java?
3. What is Null-safety in Kotlin
4. What Null Assertion in Kotlin
4. What are data types available in Kotlin?
4. What access modifiers are available in Kotlin?
5. What is Sealed, Open , Final and Data Class in Kotlin and what are it's equivalent in Java?
17. What are functionality data class provides
16. what are open class and sealed class 
6. What is Companion object in Kotlin? With Demo
14. What is difference between val and var
6. What is different between companion object and val?
6. What is different between companion object and const val?
46. What is difference between companion object and object?
7. What is difference between lazy and lateinit?
55. What is const val vs companion in kotlin
8. what is difference between val and var
13. What is difference between this and super keyword
18.What is Work WorkManager, JobShedular, JobDispatcher, AlarmManager, BroadCastReceiver
19. What is asyncTask? Why to use them.
20. What is Coroutines. When to use them.
21. Why to use threading over normal coroutines?.
22. Will you use coroutines if CPU has one core?.
23. How to call coroutines function?.
24. What is Singleton in Kotlin?
25. How to pass header in retrofit in kotlin
26. What are higher Order Function. 
27. What does clip to padding do?
28. How to create custom View in android?
29. What is content Provider and Content Resolver in android
29. What are Storage Option available in android?
37. How to write test using JUnit and Mockito class in kotlin.
38. How to write UI test using Espresso
34. How Does fragment interact with ViewModel
30. How does observer work?
9. What is View-Model how does it works?
31. How does ViewModel Interact with UI?
32. Can MVVM have two viewModel?
39. How to use LiveData in ViewModel
40. Can we write ViewModel inside View?
41. What is use of repository in MVVM?
43. How to write if-else statement in kotlin
44. Why Mvvm Invented?
45. How Does SetValue() and PostValue work in LiveData?
47. What is safe call and Non-null assertion?
48. What is extension function in kotlin?
49. How do you write to network calls for coroutines?
50. What do you use multiple header call in Api?
51. What are Android Jetpack Components
52. How does Coroutines Work INternally
53. How to create your own Coroutines
54. How Kotlin Coroutines compare to other tools like Thead, RxKotlin on work?
56. How to pass single instance of Application?
57. How Database on to many  and many to one relationship?
58. When onStop and onResume be called in android?
59. Difference between .apply and .commit in fragment?
60. How to pass data from activity to fragment?
61. What is difference between activity travelling, fragment transection?
42. What are higher Order Function in kotlin?
35. What is Flow in Kotlin
12. What is let,apply, with syntax in kotlin?
36. What are scope function?
11. What are Scope Function?


**Recommended: Please solve it first, before moving on to the solution.**

**DSA Concepts**

1. What are different types of data stucture (Difference between Linear and Non Linear DS)
2. Write a string in reverse order 
   Input "martial coder" 
   Result "redoc laitram"
3. Write a program to count greatest among 0 and 1 substring
4. Write a program using Linkedin List and print the head of the linked list , print Linked List in 
          cyclic order "1 2 3 4 5"
          result       "5 4 1 2 3 "


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THIRD PARTY LIBRARIES SOMETIME ASKED

1. What is default Image In Android
2. What is Volley ,  Android Retrofit , Which one is fast, When to choose when?
3. What is default Networking API in android
4. What is GCM server and firebase?
5. How to sent payload in notification Using firebase firebase?
6. How to integrate firebase notification  in android?
7.What is Rx Java? How to use it
8. What is Rx Kotlin? How to use it.
9. What is Wave Loading? How to use view like shimmerView Skeleton Layout to View?
10. How to integrate authentication system in android ?
11. Ho to use realm?
12. How to create a api in Spring Hibernate?