What we'll cover:
Interfaces
Classes
Data classes
Access modifiers
Object declarations
Kotlin, like Java, is a class-based, object-oriented language. It uses interfaces and classes to define custom types. The way Kotlin works with types will feel very similar to the way we’ve worked in Java, but there are also some areas where Kotlin will not feel like we’re in familiar ground. In this chapter, we’ll explore those similarities and differences.
Interfaces
The basic form of an interface in Kotlin, like in Java, looks something like the code in Listing 4-1.
interface Fax { ...
