Switch expressions & pattern matching

Switch that returns a value

Since Java 14, switch can be an expression using the arrow form — no break, no fall-through, and it produces a value:

String name = switch (day) {
    case 1 -> "Mon";
    case 2, 3 -> "midweek";   // multiple labels
    default -> "?";
};

Each arm is independent — there is no fall-through. Multiple labels share an arm with commas. For a multi-statement arm, use a block and yield to produce the value:

int size = switch (s) {
    case "S" -> 1;
    default -> {
        int n = compute(s);
        yield n;
    }
};

Modern switches also support pattern matching (Java 21): case Integer i -> matches by type and binds i. With sealed types the compiler can even check exhaustiveness.