Simple scala code: Returning first element from string array

Question

I don't know how to fix this code. It "explodes" somewhere in returnFirstString but I don't know why. Also, I don't know how to properly display result using println. Is this approach ok.

So here's the code:

def returnFirstString(a: Array[String]): Option[String]=
{
    if(a.isEmpty) { None }
    Some(a(0))
}
val emptyArrayOfStrings = Array.empty[String]
println(returnFirstString(emptyArrayOfStrings))

Noah · Accepted Answer · 2013-02-25 19:21:19Z

16

You're not properly returning the None:

  def returnFirstString(a: Array[String]): Option[String] = {
    if (a.isEmpty) {
      None
    }
    else {
      Some(a(0))
    }
  }

Also, there's already a method for this on most scala collections:

emptyArrayOfStrings.headOption

edited Feb 25, 2013 at 19:21

answered Feb 25, 2013 at 19:14

Noah

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pedrofurla · Accepted Answer · 2013-02-25 19:15:56Z

5

The most concise way:

def returnFirstString(a: Array[String]): Option[String]= a.headOption

answered Feb 25, 2013 at 19:15

pedrofurla

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