斯卡拉：我怎么能由他们的第二个元素进行排序元组的数组？ [英] Scala: how can I sort an array of tuples by their second element?

问题描述

有没有在斯卡拉的方式使用排序元组数组和任意比较函数？特别是我需要通过他们的第二个元素进行排序和元组的数组，但我想知道一般的技术，元组数组进行排序。

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.

谢谢！

推荐答案

您可以使用此code：

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))

偏偏，似乎斯卡拉不能推断传递到 stableSort 数组的类型。我希望这是确定适合你。

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

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