Switch expressions (Java 14+) vs classic switch — yield and exhaustiveness?

Switch expressions

Switch can be an expression returning a value—use -> arrows without fall-through. yield supplies value in statement blocks; compiler checks exhaustiveness for sealed/enums.

• No accidental fall-through with arrow syntax.
• Exhaustive switch on enum/sealed types catches missing cases at compile time.
• case null allowed in pattern switches (Java 21+).
• Classic colon switch still exists for side-effect style.

String label = switch (status) {
    case NEW -> "pending";
    case PAID -> "done";
    case CANCELLED -> { log(status); yield "cancelled"; }
};