Demonstration of closure in Scala

closure.scala

package otherscope {
  class Foo {
  // a method that takes a function and a string, and passes the string into
  // the function, and then executes the function
    def exec(f:(String) => Unit, name: String) {
      f(name)
    }
  }
}

object ClosureExample extends App {
  var hello = "Hello"
  def sayHello(name: String) { println(s"$hello, $name") }

  // execute sayHello from the exec method foo
  val foo = new otherscope.Foo
  foo.exec(sayHello, "Al")

  // change the local variable 'hello', then execute sayHello from
  // the exec method of foo, and see what happens
  hello = "Hola"
  foo.exec(sayHello, "Lorenzo")
}