int val = switch (str) {
case "foo" -> 1;
case "bar" -> 2;
case "baz" -> 3;
default -> -1;
}
val foo = match (str) {
case "foo" => 1
case "bar" => 2
case "baz" => 3
case _ => -1
}
> We are "reclaiming" the syntactic real estate of "_" from the space of identifiers for use in future language features. However, because there are existing programs that might use it, it is a warning for identifiers that occur in existing syntactic positions for 8, and an error for lambda formals (since there is no existing code with lambdas.)
Example:
BiFunction<Integer, String, String> biss = (i, _) -> String.valueOf(i);
And citing this JEP 302:
We are now free to complete the planned rehabilitation of underscore
to indicate an unused lambda, method, or catch formal parameter. val emails = users.map(_.email)