What is is “(x, y)” in Scala, and what is actually being returned?

Question

scala> def check(a: Int, b: Int): (Int, Int) = {
      (3, 4)
      }

The returning type is (Int, Int). How is this possible? What is S

Answer 1

As @dhg mentioned, (Int, Int) is equals to Tuple2[Int, Int]

In second sample you use pattern matching in variable definition. You can use it with tuples, case classes and with everything which has extractors. Actually, everything works via extractors.

scala> val p = Point(1, 2)
p: Point = Point(1,2)

scala> val Point(x, y) = p
x: Int = 1
y: Int = 2

scala> val Property = "(.+)=(.+)".r
Property: scala.util.matching.Regex = (.+)=(.+)

scala> val Property(name, value) = "name1=value1"
name: String = name1
value: String = value1

Answer 2

The type (Int, Int) is just a nicer way of writing Tuple2[Int,Int]