CODEWITHSUNDEEP
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hispaniccoder
hispaniccoder

Reputation: 397

How to apply flatMap to list of tuples (Int,String) in Scala?

I have the following List of tuples in Scala:

var a : List[(Int,String)] = List()
a = a:+((1,"bla bla bla"))
a = a:+((2,"la la la"))
a = a:+((3,"bla la bla"))

which looks like that:

print(a)
List((1,bla bla bla), (2,la la la), (3,bla la bla))

What I wish to do is to apply flatMap function in order to create a new list from the list a which contains only the strings from the tuple to which it appends the word "appended". The result should therefore be:

List(bla bla blaappended, la la laappended, bla la blaappended)

Could someone help me understand how I could go about it? I am new to Scala and I can't wrap my head around this. Thanks in advance

Upvotes: 1

Views: 357

Answers (2)

Luis Miguel Mejía Suárez
Luis Miguel Mejía Suárez

Reputation: 22885

You do not want flatMap you want just a map, because you only want to perform a one to one transformation.
Also, for this kind of situations pattern matching is very helpful.
(BTW, consider reading all the tour and other basic tutorials)

// Avoid mutability ;)
val list : List[(Int,String)] = List(
  1 -> "bla bla bla",
  2 -> "la la la",
  3 -> "bla la bla"
)

val result = list.map {
  case (_, str) => s"${str} appended"
}

Upvotes: 3

Andronicus
Andronicus

Reputation: 26056

You don't need flatMap, simple map is enough

val result = a.map(t => t._2 + "appended")

Upvotes: 1

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