Scala and Spark for Big Data Analytics

Companion objects

When a singleton object is named the same as a class, it is called a companion object. A companion object must be defined inside the same source file as the class. Let's demonstrate this with the example here:

class Animal {  var animalName:String  = "notset"  def setAnimalName(name: String) {    animalName = name  }  def getAnimalName: String = {    animalName  }  def isAnimalNameSet: Boolean = {    if (getAnimalName == "notset") false else true  }}

The following is the way that you will call methods through the companion object (preferably with the same name - that is, Animal):

object Animal{  def main(args: Array[String]): Unit= {    val obj: Animal = new Animal    var flag:Boolean  = false            obj.setAnimalName("dog") flag = obj.isAnimalNameSet ...