Kotlin

Main

• Describe null safety
• What is the difference between nested classes and inner classes?
• What's Companion Objects?
• What scope function do you know?
• Describe visibility modifiers
• What do you know about Any, Nothing, Unit types?
• What do you know about default methods in interface?
• What is destructuring declarations?
• What is Ranges?
• What is Sequence?
• What is the difference between == and === ?
• What is infix function?
• What is init block?
• What do you know about delegated properties?
• What do you know about JvmOverloads annotation?

Classes

• What do you know about data classes?
• What do you know about sealed classes?
• What do you know about inline classes?

Keywords

• What do you know about Object keyword?
• What do you know about inline keyword?
• What do you know about crossinline keyword?
• What do you know about reified keyword?
• What do you know about const keyword?
• What do you know about lateinit keyword?
• What is the difference between lazy and lateinit?

Structured concurrency

• What are coroutines?
• What is the difference between suspending and blocking?
• What do you know about Channels?
• What do you know about Flow?
• What do you know about StateFlow?

Collections

• What do you know about collections?
• val mutableList vs var immutableList. When to use which one?
• What is the difference between fold and reduce?
• What is the difference between map and flatMap?