CODEWITHSUNDEEP
scalascala-collections
axnet
axnet

Reputation: 5790

How to get comma separated values from List of Maps in Scala?

I have listMap1 variable of type List[Map [String, String]] and I want all values associated with key 'k1' as one string with comma separated values 

import fiddle.Fiddle, Fiddle.println
import scalajs.js

@js.annotation.JSExport
object ScalaFiddle {

  var m1:Map[String,String] = Map(("k1"->"v1"), ("k2"->"vv1")) 
  var m2:Map[String,String] = Map(("k1"->"v2"),("k2"->"vv2"))
  var m3:Map[String,String] = Map(("k1"->"v3"),("k2"->"vv3"))

  var listMap1 = List(m1,m2,m3)
  var valList = ??  // need all values assoicated with k1 like -->  v1,v2,v3...
}

Upvotes: 1

Views: 1366

Answers (2)

Lee
Lee

Reputation: 144136

A simple approach would be:

listMap1.flatMap(_.get("k1")).mkString(",")

be warned that this will not work if you're generating CSV data and the associated values contain ,s e.g. Map(("k1" -> "\some, string"))

Upvotes: 7

Pavel
Pavel

Reputation: 1539

is that ok ?? 

  val r = listMap1.filter(l => l.contains("k1") ).map(r => r("k1") ).mkString(",")

Upvotes: 1

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