Singleton & Companion Objects

Singleton Objects

A singleton object is a class with exactly one instantiated lazy object. Syntax:

object objectName{
  // Internal object definitions.
}

An object can be imported into a class using the keyword import as follows:

import objectName._

Companion Objects

In a Scala source file, if a singleton object is defined with the same name as a class, then that object is said to be a companion to that class. If an object and a class are companions, then either of them can access the other's private members such as variables, objects and methods.

For more information about singleton and companion objects, please visit Scala's Documentation.