Why do we need break after case statements?

Question

Why doesn\'t the compiler automatically put break statements after each code block in the switch? Is it for historical reasons? When would you want multiple code blocks to e

Answer 1

As people said before, it is to allow fall-through and it is not a mistake, it is a feature. If too many break statements annoy you, you can easily get rid of them by using return statements instead. This is actually a good practice, because your methods should be as small as possible (for the sake of readability and maintainability), so a switch statement is already big enough for a method, hence, a good method should not contain anything else, this is an example:

public class SwitchTester{
    private static final Log log = LogFactory.getLog(SwitchTester.class);
    public static void main(String[] args){
        log.info(monthsOfTheSeason(Season.WINTER));
        log.info(monthsOfTheSeason(Season.SPRING));
        log.info(monthsOfTheSeason(Season.SUMMER));
        log.info(monthsOfTheSeason(Season.AUTUMN));
    }

    enum Season{WINTER, SPRING, SUMMER, AUTUMN};

    static String monthsOfTheSeason(Season season){
        switch(season){
            case WINTER:
                return "Dec, Jan, Feb";
            case SPRING:
                return "Mar, Apr, May";
            case SUMMER:
                return "Jun, Jul, Aug";
            case AUTUMN:
                return "Sep, Oct, Nov";
            default:
                //actually a NullPointerException will be thrown before reaching this
                throw new IllegalArgumentException("Season must not be null");
        }        
    }
}   

The execution prints:

12:37:25.760 [main] INFO lang.SwitchTester - Dec, Jan, Feb
12:37:25.762 [main] INFO lang.SwitchTester - Mar, Apr, May
12:37:25.762 [main] INFO lang.SwitchTester - Jun, Jul, Aug
12:37:25.762 [main] INFO lang.SwitchTester - Sep, Oct, Nov

as expected.