Is it possible to match on a comparison using the pattern matching system in Scala? For example:
a match {
case 10 => println("ten")
case _ > 10 => println("greater than ten")
case _ => println("less than ten")
}
The second case statement is illegal, but I would like to be able to specify "when a is greater than".
ベストアンサー1
You can add a guard, i.e. an if and a boolean expression after the pattern:
a match {
case 10 => println("ten")
case x if x > 10 => println("greater than ten")
case _ => println("less than ten")
}
Edit: Note that this is more than superficially different to putting an if after the =>, because a pattern won't match if the guard is not true.