Using VI Java from Scala

Using VI Java from Scala

• 1.
  Using VI Javafrom Scala Dave “Bric” Briccetti, Contractor at VMware Dave Briccetti Software LLC davebsoft.com @dcbriccetti
• 2.
  VI Java forPerformance Graphs
• 3.
  HelloVM.scala
• 4.
  Quick Intro toScala (Enough to read the code) ● val and var ● List ● Array ● map ● Singleton object ● match
• 5.
  val and var ● val creates a final variable val x = 1 x=2 error: reassignment to val var x = 1 x=2
• 6.
  List ● val nums = List(2,5,8) nums: List[Int] = List(2, 5, 8) nums.size res9: Int = 3
• 7.
  Array ● val nums = Array(1,5,7) nums: Array[Int] = Array(1, 5, 7) nums.toList res8: List[Int] = List(1, 5, 7)
• 8.
  map ● val nums = List(2,5,8) nums: List[Int] = List(2, 5, 8) nums.map(_ + 1) res10: List[Int] = List(3, 6, 9)
• 9.
  Singleton Object ● Java types: ● class ● interface ● Scala types: ● class ● trait ● object ● object is like a preinstantiated object of a class, with all members static
• 10.
  match ● List(2) match { case first :: rest => "First: " + first + ", rest: " + rest case _ => "no match" } res17: java.lang.String = First: 2, rest: List() ● List(2,3) match { case first :: rest => "First: " + first + ", rest: " + rest case _ => "no match" } res18: java.lang.String = First: 2, rest: List(3)
• 11.
  Unit Test
• 12.
  HelloVM Part 1
• 13.
  HelloVM Part 2
• 14.
  HelloVM Part 3
• 15.
  Summary ● The Java Virtual Machine runs many languages, including Scala ● VI Java can be used by any of these languages ● Scala is a powerful language, which interoperates very well with Java libraries like VI Java Dave Briccetti Software LLC davebsoft.com @dcbriccetti