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Question

I want to check if a Map doesn't contain empty values. If the value is empty it shouldn't includen in the new Map.

I tried something like:

val newmap = map.map{ entry => if(!entry._2.isEmpty()) Map(entry._1 -> entry._2)}

This does exactly do what I want, but it is not very nice. Is there a better solution?

Answer 1

scala> Map(1 -> List(3, 4), 2 -> Nil, 3 -> List(11))
res2: scala.collection.immutable.Map[Int,List[Int]] = Map(1 -> List(3, 4), 2 -> List(), 3 -> List(11))

scala> res2.filter(_._2.nonEmpty)
res3: scala.collection.immutable.Map[Int,List[Int]] = Map(1 -> List(3, 4), 3 -> List(11))

scala>

Answer 2

You mean empty as in null?

scala> val map = collection.immutable.HashMap[Int, String] (1 -> "a", 2-> "b", 3 -> null)
map: scala.collection.immutable.HashMap[Int,String] = Map(1 -> a, 2 -> b, 3 -> null)

scala> val newmap=map filter (_._2 != null)
newmap: scala.collection.immutable.HashMap[Int,String] = Map(1 -> a, 2 -> b)

EDIT: dang... @missingfaktor beat me to it... :)