I am very new to Scala, and I am not sure how this is done. I have googled it with no luck. let us assume the code is:
var arr = readLine().split(" ")
Now arr is a string array. Assuming I know that the line I input is a series of numbers e.g. 1 2 3 4, I want to convert arr to an Int (or int) array.
I know that I can convert individual elements with .toInt, but I want to convert the whole array.
Thank you and apologies if the question is dumb.
Applying a function to every element of a collection is done using .map :
scala> val arr = Array("1", "12", "123")
arr: Array[String] = Array(1, 12, 123)
scala> val intArr = arr.map(_.toInt)
intArr: Array[Int] = Array(1, 12, 123)
Note that the _.toInt notation is equivalent to x => x.toInt :
scala> val intArr = arr.map(x => x.toInt)
intArr: Array[Int] = Array(1, 12, 123)
Obviously this will raise an exception if one of the element is not an integer :
scala> val arr = Array("1", "12", "123", "NaN")
arr: Array[String] = Array(1, 12, 123, NaN)
scala> val intArr = arr.map(_.toInt)
java.lang.NumberFormatException: For input string: "NaN"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.parseInt(Integer.java:615)
at scala.collection.immutable.StringLike$class.toInt(StringLike.scala:272)
...
... 33 elided
Starting Scala 2.13, you might want to use String::toIntOption in order to safely cast Strings to Option[Int]s and thus also handle items that can't be cast:
Array("1", "12", "abc", "123").flatMap(_.toIntOption)
// Array[Int] = Array(1, 12, 123)
