Scala and Spark for Big Data Analytics

Pattern matching

One of the widely used features of Scala is pattern matching. Each pattern match has a set of alternatives, each of them starting with the case keyword. Each alternative has a pattern and expression(s), which will be evaluated if the pattern matches and the arrow symbol => separates pattern(s) from expression(s). The following is an example which demonstrates how to match against an integer:

object PatternMatchingDemo1 {  def main(args: Array[String]) {    println(matchInteger(3))  }     def matchInteger(x: Int): String = x match {    case 1 => "one"    case 2 => "two"    case _ => "greater than two"  }}

You can run the preceding program by saving this file in PatternMatchingDemo1.scala and then using the following commands to run it. Just ...