Functions

Kotlin functions are first-class, which means that they can be stored in variables and data structures, passed as arguments to and returned from other higher-order functions. You can operate with functions in any way that is possible for other non-function values.

• Extension functions
• Higher-Order /Lambdas/ Reciever functions
• Inline functions

Classes

• Data classes
• ADT using Sealed classes

Collections

• Kotlin Collections: Grouping and some function