Singleton in Kotlin

In the Kotlin programming language, a singleton is a design pattern that allows you to create only one instance of a class. This is useful when you want to make sure that there is only one instance of a particular class, for example, if you want to create a global object that can be accessed from anywhere in your code. Here is an example of how you might implement a singleton in Kotlin:

class Singleton private constructor() {
    companion object {
        private var instance: Singleton? = null

        fun getInstance(): Singleton {
            if (instance == null) {
                instance = Singleton()
            }
            return instance
        }
    }
}

In this example, we have a class called Singleton that has a private constructor, which means that it cannot be instantiated directly. Instead, we have a companion object with a static method called getInstance() that is used to create and return the single instance of the Singleton class. The first time getInstance() is called, it creates a new instance of Singleton and stores it in a static variable called instance. Subsequent calls to getInstance() simply return the instance that was created the first time.