Hands-On Design Patterns with Kotlin

Declaring functions

Everything is an object in Java. If you have a method that doesn't rely on any state, it still must be wrapped by a class. You're probably familiar with a lot of Util classes in Java that only have static methods, and their only purpose is to satisfy the language requirements and bundle those methods together.

In Kotlin, a function can be declared outside of a class instead of the following code:

public class MyFirstClass {

    public static void main(String[] args) {        System.out.println("Hello world");    }}

It's enough to have:

fun main(args: Array<String>) {    println("Hello, world!")}

Functions declared outside of any class are already static.

Many examples in this book assume that the code we provide is wrapped in the main ...