How to convert a whole list of string to integer values in Scala

Question

So, I have a list of strings like this.

val x = List("12", "33", "77")

Is there a way to convert this whole List into integer values, like the following, without using a for loop?

result == List(12, 33, 77)

Vow, this syntax is awesome. Scala seems a pretty cool language. — MetallicPriest
– MetallicPriest, Commented Nov 15, 2014 at 16:54

Michael Zajac · Accepted Answer · 2014-11-15 17:12:56Z

4

map the List using toInt :

List("12", "33", "77").map(_.toInt)

Or with a little more safety:

import scala.util.{Success, Try}
List("12", "33", "77", "bad").map(s => Try(s.toInt))
    .collect { case Success(x) => x }

res2: List[Int] = List(12, 33, 77)

Also:

List("12", "33", "77", "bad").filter(_.matches("[0-9]+")).map(_.toInt)
res7: List[Int] = List(12, 33, 77)

edited Nov 15, 2014 at 17:12

answered Nov 15, 2014 at 16:52

Michael Zajac

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Comments

elm · Accepted Answer · 2014-11-15 17:17:12Z

2

Using flatMap over util.Try like this,

x.flatMap( s => Try(s.toInt) toOption )
res: List[Int] = List(12, 33, 77)

answered Nov 15, 2014 at 17:17

elm

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1 Comment

The Archetypal Paul Over a year ago

That wiil silently discard bad entries

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