switch-case statement without break

• If you don't include break in any of case then all the case below will be executed and until it sees break.

• And if you don't include break in default then it will cause no effect as there are not any case below this 'Default' case.

• And not using break generally considered as a bad practice but some time it may also come handy because of its fall-through nature.For example:

  case optionA:

  //optionA needs to do its own thing, and also B's thing.
  //Fall-through to optionB afterwards.
  //Its behaviour is a superset of B's.
  

  case optionB:

  // optionB needs to do its own thing
  // Its behaviour is a subset of A's.
  break;
  

  case optionC:

  // optionC is quite independent so it does its own thing.
  break;
  

You execute everything starting from the selected case up until you see a break or the switch statement ends. So it might be that only C is executed, or B and then C, or A and B and C, but never A and C