jonjack/scala-snippets.md

## scala-snippets.md

      
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              scala-snippets.md
            
          
    Return the max value of a List[Int] if unique, otherwise return -1.
def maxIfUnique(li: List[Int]) = li.groupBy(_.intValue).maxBy(_._1)._2 match {
  case x if x.size == 1 => x.head
  case _ => -1
}

scala> val list = List(1, 2, 1)   // 2 is max and is unique
scala> maxIfUnique(list)
res61: Int = 2

scala> val list = List(3, 3, 1)   // 3 is max but not unique
scala> maxIfUnique(list)
res62: Int = -1