Kotlin Programming: The Big Nerd Ranch Guide, First Edition

Implementing an Interface

To use an interface, we say that you “implement” it on a class. There are two parts to this: First, you declare that the class implements the interface. Then, you must ensure that the class provides implementations for all of the properties and functions specified in the interface.

Use the : operator to implement the Fightable interface on Player.

Listing 16.2  Implementing an interface (Player.kt)

class Player(_name: String,
        override var healthPoints: Int = 100,
        var isBlessed: Boolean = false,
        private var isImmortal: Boolean) : Fightable {
    ...
}

When you add the Fightable interface to Player, IntelliJ indicates that functions and properties are missing. Warning you that properties and functions ...