Kotlin Programming: The Big Nerd Ranch Guide, First Edition

Defining Generic Types

A generic type is a class that accepts an input of any type in its constructor. You are going to begin by defining your own generic type.

Open the Sandbox project and add a new file called Generics.kt. Within Generics.kt, define a LootBox class that specifies a generic type parameter for use with its contents and contains a private property called loot that is assigned the item.

Listing 17.1  Creating a generic type (Generics.kt)

class LootBox<T>(item: T) {
    private var loot: T = item
}

You define the LootBox class and make it generic by specifying a generic type parameter for use with the class, written as T and specified within diamond braces (< >) like other type parameters. The generic type parameter, ...