Programming Kotlin

Designing with Delegates

In the previous chapter, you saw that Kotlin offers a different and safer way to use inheritance than Java. Likewise, Kotlin has much better support than Java for delegation. Before we dive into the syntax for delegation, we’ll take a small problem and design it using inheritance, to better understand the reasons to use delegation over inheritance. Soon we’ll run into issues where inheritance begins to become a hindrance, and you’ll see how delegation may be a better choice for the problem. We’ll then look at how Kotlin is able to readily support our new design using delegation, without flinching.

A Design Problem

Imagine an application that simulates the execution of software projects by corporate teams (don’t worry, ...