Wraps the related properties and methods that perform action on those properties in a class. There are four basic concepts of OOP, each of which you learn more about later in this codelab: OOP helps you simplify complex, real-world problems into smaller objects. To know how to design your classes, you need to get familiar with object-oriented programming (OOP), a framework that teaches you to enclose data, logic, and behavior in objects. Just like the house blueprint specifies multiple rooms and each room has its own design and purpose, each class has its own design and purpose. The house is the actual thing, or object, which is built based on the blueprint. The blueprint isn't the house it's the instruction for how to build the house. A class is similar to an architect's design plan, also known as a blueprint. You can use objects or class instances interchangeably.Īs an analogy, imagine that you build a house. An object is an instance of a class that consists of data specific to that object. Therefore, even if you aren’t going to write Java code, I still recommend that you read the previous article before proceeding with this one.This codelab teaches you how to use classes and objects in Kotlin.Ĭlasses provide blueprints from which objects can be constructed. Except for specific code examples, that article contains much theoretical discussion which I don’t intend to repeat here. Note that in my previous post I showed several approaches to implement use cases in Java. In this post, I’ll describe how you can implement use cases in Kotlin.

Use case classes, also known as interactors, are probably the most recognizable aspect of “Clean Architecture” school of thought.

Internal keyword in kotlin