OO state

FooState

class Foo{
  private var fooState = 0
  def  next:Int = { fooState = fooState + 1;  fooState  }
  def getFooState:Int = fooState
}

val foo = new Foo()
foo.next
foo.next
val result = foo.next
println("foo="+foo.getFooState)  // foo=3