How to pattern match using regular expression in Scala?

regex scala

Bruce Ferguson · Jan 8, 2011 · Viewed 156.3k times · Source

I would like to be able to find a match between the first letter of a word, and one of the letters in a group such as "ABC". In pseudocode, this might look something like:

case Process(word) =>
   word.firstLetter match {
      case([a-c][A-C]) =>
      case _ =>
   }
}

But how do I grab the first letter in Scala instead of Java? How do I express the regular expression properly? Is it possible to do this within a case class?

Answer

You can do this because regular expressions define extractors but you need to define the regex pattern first. I don't have access to a Scala REPL to test this but something like this should work.

val Pattern = "([a-cA-C])".r
word.firstLetter match {
   case Pattern(c) => c bound to capture group here
   case _ =>
}

How to pattern match using regular expression in Scala?

Answer

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