Question

is there a way in Scala to sort an array of tuples using and arbitrary comparison function? In particular I need to sort and array of tuples by their second element, but I wanted to know a general technique to sort arrays of tuples.

Thanks!

Answer 1

You can use this code:

scala> val v = Array(('a', 2), ('b', 1))
v: Array[(Char, Int)] = Array((a,2), (b,1))

scala> scala.util.Sorting.stableSort(v,
     | (e1: (Char, Int), e2: (Char, Int)) => e1._2 < e2._2)

scala> v
res11: Array[(Char, Int)] = Array((b,1), (a,2))

Unfortunetly, it seems that Scala cannot infer the type of the array passed to stableSort. I hope that’s ok for you.