Kotlin Academy · Lesson

object Declaration: Kotlin Singletons

Create singletons with object and understand their lifecycle.

object as a Singleton

An object declaration creates a single instance — a thread-safe, lazily-initialized singleton — with one line of code.

Use object Name { ... } to declare a singleton with state and methods.

object Logger {
    fun log(msg: String) = println("[LOG] $msg")
}
fun main() {
    Logger.log("App started")
    Logger.log("User signed in")
}