Is it possible to have tuple assignment to variables in Scala? [duplicate]

Question

Possible Duplicate:
Tuple parameter declaration and assignment oddity

In Scala, one can do multiple-variable assignment to tuples via:

val (a, b) = (1, 2) 

But a similar syntax for assignment to variables doesn't appear to work. For example I'd like to do this:

var (c, d) = (3, 4) (c, d) = (5, 6) 

I'd like to reuse c and d in multiple-variable assignment. Is this possible?

Answer 1

This isn't simply "multiple variable assignment", it's fully-featured pattern matching!

So the following are all valid:

val (a, b) = (1, 2) val Array(a, b) = Array(1, 2) val h :: t = List(1, 2) val List(a, Some(b)) = List(1, Option(2)) 

This is the way that pattern matching works, it'll de-construct something into smaller parts, and bind those parts to new names. As specified, pattern matching won't bind to pre-existing references, you'd have to do this yourself.

var x: Int = _ var y: Int = _  val (a, b) = (1, 2) x = a y = b  // or  (1,2) match {   case (a,b) => x = a; y = b   case _ => }