CODEWITHSUNDEEP
scalacollections
javier_orta
javier_orta

Reputation: 477

how can i match two collections in scala by a field equality

i have this code :

case class DataText(name:String)
  val dataModels = Seq(DataText("a.dm"),DataText("b.dm"),DataText("c.dm"),DataText("d.dm"),DataText("e.dm"),DataText("f.dm"))
  val dataReports = Seq(DataText("a.d0"),DataText("b1.do"),DataText("c2.do"),DataText("d.do"),DataText("e3.do"),DataText("f5.do"))

how can i match dataModels and dataReports, when an item in dataModels split by "." like name.split(".").head can match to dataReports split by "." like name.split(".").head

The result could be:

Seq(DataText("a.dm"),DataText("d.dm"))

i have tried with map and an embedded filter but don't work.

Upvotes: 0

Views: 38

Answers (1)

Leo C
Leo C

Reputation: 22439

I would transform dataReports into a Set of the target sub-elements for filtering via contains (which is a constant time O(1) operation):

val dataReportsSet = dataReports.map(_.name.split("\\.")(0)).toSet

dataModels.filter(dm => dataReportsSet.contains(dm.name.split("\\.")(0)))
// res1: Seq[DataText] = List(DataText(a.dm), DataText(d.dm))

Upvotes: 1

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