Scala and Spark for Big Data Analytics

Constructor in Scala

One surprising thing about Scala is that the body of a Scala class is itself a constructor. However, Scala does so; in fact, in a more explicit way. After that, a new instance of that class is created and executed. Moreover, you can specify the arguments of the constructor in the class declaration line.

Consequently, the constructor arguments are accessible from all of the methods defined in that class. For example, the following class and constructor definition is valid in Scala:

class Hello(name: String) {  // Statement executed as part of the constructor  println("New instance with name: " + name)  // Method which accesses the constructor argument  def sayHello = println("Hello, " + name + "!")}

The equivalent Java class ...