String to Int in Scala - scala

Question

Suppose I need to convert a String to Int in Scala. If the string is not a number I would like to return None rather than throw an exception.
I found the following solution
def toMaybeInt(s:String) = {
import scala.util.control.Exception._
catching(classOf[NumberFormatException]) opt s.toInt
}
Does it make sense ? Would you change/improve it ?

Answer 1

I'd use scala.util.Try which returns Success or Failure for a computation that may throw an exception.
scala> val zero = "0"
zero: String = 0
scala> val foo = "foo"
foo: String = foo
scala> scala.util.Try(zero.toInt)
res5: scala.util.Try[Int] = Success(0)
scala> scala.util.Try(foo.toInt)
res6: scala.util.Try[Int] = Failure(java.lang.NumberFormatException: For input string: "foo")
So, toMaybeInt(s: String) becomes:
def toMaybeInt(s:String) = {
scala.util.Try(s.toInt)
}

Answer 2

For getting an option in any case, regardless of possible exceptions due to number malformation,
import scala.util.Try
def toOptInt(s:String) = Try(s.toInt) toOption
Then
scala> toOptInt("123")
res2: Option[Int] = Some(123)
scala> toOptInt("1a23")
res3: Option[Int] = None
Further, consider
implicit class convertToOptInt(val s: String) extends AnyVal {
def toOptInt() = Try(s.toInt) toOption
}
Hence
scala> "123".toOptInt
res5: Option[Int] = Some(123)
scala> "1a23".toOptInt
res6: Option[Int] = None