A very common example:
switch (month) {
case 2:
if(isLeapYear)
days = 29;
else
days = 28;
break;
case 4:
case 6:
case 9: // do the same thing
case 11:
days = 30;
break;
default:
days = 31;
}
From the above example - you get a much cleaner code, and also, you have more flexibility than you would have if the switch required to break out implicitly after every case.
