Hands-On Design Patterns with Kotlin

Constants

Since everything in Java is an object (unless you're a primitive type), we're used to putting all the constants inside our objects as static members.

And since Kotlin has companion objects, we usually try putting them there:

class MyClass {    companion object {        val MY_CONST = "My Const"    }}

This will work, but you should remember that companion object is an object, after all.

So, this will be translated to the following code, more or less:

public final class Spock {   @NotNull   private static final String MY_CONST = "My Const";   public static final Spock.Companion Companion = new Spock.Companion(...);   public static final class Companion {      @NotNull      public final String getMY_CONST() {         return MyClass.MY_CONST;      }      private Companion() {      } } ...