Essential Android Interview Questions from RocketSkill Application

Interview Questions for getting you ready for your interview A small guide to help those looking to hire a developer for android. A great self-test if you're looking to keep current or practice for your own interview. All you need to know about android technical interview including some tips for preparing, questions and some coding exercises

Android domains

We have organized the questions to better address each focus point.

• Platform
• Memory Management
• Kotlin
• Java
• Basic Classes
• Algorithms
• Security
• Tools
• Internationalization-Localization
• Design Pattern
• Data Storage
• PlayStore

Platform

• What is Android?
• who founded it?
• What is Context?
• Application Context
• Activity Context
• Services
• Intent
• Explicit/implicit Intent
• Resource Externalization (strings and graphics)
• Notification (light,sound,icon,notification,dialog box,and toast)
• Content Providers
• Activity
• Fragment
• APK
• Explicit/implicit Intent
• What is An android manifest file?
• nine-patch images?
• PNG, SVG support?
• How to launch an activity in android?
• How do you pass the data to an activity?
• How do you pass the data to a fragment?
• How familiar you are with the Android and Google Guidelines?
• What are the four states of the Activity Lifecycle?
• What is the difference between Serializable and Parcelable?
• What is AndroidManifest.xml used for?
• What is the difference between Service and IntentService?
• Can you name the 7 life-cycle methods of Android activity and explain a little about each one?

Memory Management

• How is manage the memory? Garbage?
• What is ANR?
• DVM (Dalvik Virtual Machine)
• JVM(Java Virtual Machine)
• ART
• What is ADB?
• What is a Thread?
• ARMv7 / ARM64 /ARMx86
• What is bytecode?

Kotlin

• What is Kotlin?
• Why kotlin is better than Java?
• How to declare a variable in kotlin?
• What’s the Target Platform of Kotlin? How is Kotlin-Java interoperability possible?
• How do you declare variables in Kotlin?
• How does the declaration differ from the Java counterpart?
• What’s the difference between val and var declaration?
• How to convert a String to an Int?
• What’s Null Safety and Nullable Types in Kotlin?
• What is the Elvis Operator?
• What’s a const? How does it differ from a val?
• Does Kotlin allow us to use primitive types such as int, float, double?
• What’s the entry point of every Kotlin Program?
• How is !!different from ?. in unwrapping the nullable values? Is there any other way to unwrap nullable values safely?
• How is a function declared? Why are Kotlin functions known as top-level functions?
• What’s the difference between == and === operators in Kotlin?
• What are the types of constructors in Kotlin? How are they different? How do you define them in your class?
• What’s init block in Kotlin
• How does string interpolation work in Kotlin? Explain with a code snippet?
• What’s the type of arguments inside a constructor?
• Is new a keyword in Kotlin? How would you instantiate a class object in Kotlin?
• What is the equivalent of switch expression in Kotlin? How does it differ from switch?
• What are data classes in Kotlin? What makes them so useful? How are they defined?
• What are destructuring declarations in Kotlin?
• What’s the difference between lazy and lateinit?
• How to create Singleton classes?
• Does Kotlin have the static keyword? How to create static methods in Kotlin?
• What’s the type of the following Array?

Java

• What are the main 3 Object Oriented Programing (OOP) concepts?
• Explain object serialization and how to implement it in Java.
• Explain anonymous classes. [info]
• Describe the differences between abstract classes and interfaces.
• Explain what a Singleton class is and how to create one in Java [info]
• Why should the equals() and hashCode() methods often be overridden together?
• How do you properly override the equals() method? For example, what considerations should be taken when checking for equality?
• Difference between final, finally and finalize?
• In Java, does the finally block gets executed if we insert a return statement inside the try block of a try-catch-finally?
• Explain method overloading & overriding.
• What is memory leak and how does Java handle it?

Design

• Explain the differences and similarities of Relative Layout and Linear Layout.
• Explain the differences and similarities of List Views and Grid Views.
• Describe how to implement XML namespaces.
• Explain how to present different styles/drawables for a button depending on the state of the button (pressed, selected, etc.) using XML (no Java)
• for layout_width and layout_height, what's the difference between match_parent and wrap_content?
• How do you implement Google's new Material Design in an Android application?
• Difference between View.GONE and View.INVISIBLE?

Basic Classes

• What are the use cases and differences of arrays and ArrayLists?
• What are the use cases and differences of a HashSet and a TreeSet?

Algorithms

IN PROGRESS

Security

IN PROGRESS

Tools

• Ant
• Maven
• Gradle
• SQLite
• Realm

Internationalization-Localization

• Translate in Android?

Design Pattern

• What is singleton class in android?
• MVC
• MVP
• MVVM
• What is dependency injection?

Data Storage

• shared preferences
• different storages available in android?
• Internal Storage
• External Storage,
• SQLite Databases

PlayStore

IN PROGRESS

Contributions

If you want to add subjets of interviews. Those subjets can be added to RocketSkill App and if you want you will be named in in the question add contributors.

• Open an issue
• Or fork and submit a merge request

Other plateforms

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