def triple(x: Int) = 3 * x // Parameter name: Type
val f = (x: Int) => 3 * x // Anonymous function
(1 to 10).map(3 * _) // Function with anonymous parameter
def greet(x: Int) { // Without =, return type is Unit
  println("Hello, " + x) }
def greet(x: Int, salutation: String = "Hello") { // Default argument
  println(salutation + ", " + x) }
// Call as greet(42), greet(42, "Hi"), greet(salutation = "Hi", x = 42)
def sum(xs: Int*) = { //* denotes varargs
  var r = 0; for (x <- xs) r += x // Semicolon separates statements on same line
  r // No return. Last expression is value of block
}
def sum(xs: Int*): Int = // Return type required for recursive functions
  if (xs.length == 0) 0 else xs.head + sum(xs.tail : _*) // Sequence as varargs