kotlin-lang

Kotlin scope functions execute blocks of code in the context of an object. Use apply for configuration, let for null checks, and also for side effects, providing concise idiomatic syntax for object initialization and transformations.

Kotlin null safety distinguishes nullable types using the question mark operator. Apply safe calls with the dot-question-mark syntax or the elvis operator to handle null values explicitly, preventing NullPointerExceptions at compile time.

Yes, Kotlin collections and generics are fully compatible with JVM-based development. Apply read-only and mutable collection interfaces, and use declaration-site variance and reified generics to write type-safe, flexible data structures.

Implement Kotlin-Java interop by applying the JvmStatic and JvmField annotations to expose APIs cleanly. Use sealed class hierarchies to represent restricted inheritance graphs, enabling exhaustive when-expressions and type-safe state modeling.

Use Kotlin delegation by applying the by keyword when you need to share behavior across unrelated classes without deep inheritance hierarchies. This approach delegates interface implementation to a separate object, promoting composition over inheritance.