Scala and Spark for Big Data Analytics

Objects in Scala

An object in Scala has a slightly different meaning than the traditional OOP one, and this difference should be explained. In particular, in OOP, an object is an instance of a class, while in Scala, anything that is declared as an object cannot be instantiated! The object is a keyword in Scala. The basic syntax for declaring an object in Scala is as follows:

object <identifier> [extends <identifier>] [{ fields, methods, and classes }]

To understand the preceding syntax, let's revisit the hello world program:

object HelloWorld {  def main(args : Array[String]){    println("Hello world!")  }}

This hello world example is pretty similar to the Java ones. The only big difference is that the main method is not inside a class, but instead ...