Kotlin Programming Cookbook

How to do it…

Follow these steps to create singletons in Kotlin:

1. Kotlin does not have static members or variables, so for declaring static members of a class, we use companion object. Check out this example:

class SomeClass {    companion object {        var intro = "I am some class. Pleased to meet you!"        fun infoIntro(): String {            return "I am some class. Pleased to meet you!"        }    }}

2. Accessing the members and methods of companion object of the preceding class is the same as we would do for any static members or methods:

var x = SomeClass.introtoast(SomeClass.infoIntro())

3. Now what if we want a singleton class, that is, the class with only one object/instance at a time? Brace yourselves, this one is fun. Here's a way to create a singleton class in ...