How to find if a Scala String is parseable as a Double or not?

Question

Suppose that I have a string in scala and I want to try to parse a double out of it.

I know that, I can just call toDouble and then catch the java num format exception if this fails, but is there a cleaner way to do this? For example if there was a parseDouble function that returned Option[Double] this would qualify.

I don't want to put this in my own code if it already exists in the standard library and I am just looking for it in the wrong place.

Thanks for any help you can provide.

Answer 1

For Scala 2.13+ see Xavier's answer below. Apparently there's a toDoubleOption method now.

For older versions:

def parseDouble(s: String) = try { Some(s.toDouble) } catch { case _ => None } 

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Fancy version (edit: don't do this except for amusement value; I was a callow youth years ago when I used to write such monstrosities):

case class ParseOp[T](op: String => T) implicit val popDouble = ParseOp[Double](_.toDouble) implicit val popInt = ParseOp[Int](_.toInt) // etc. def parse[T: ParseOp](s: String) = try { Some(implicitly[ParseOp[T]].op(s)) }                                     catch {case _ => None}  scala> parse[Double]("1.23") res13: Option[Double] = Some(1.23)  scala> parse[Int]("1.23") res14: Option[Int] = None  scala> parse[Int]("1") res15: Option[Int] = Some(1)