switch 열거문

const Direction = {
  UP:'UP',
  DOWN:'DOWN',
  LEFT:'LEFT',
  RIGHT:'RIGHT'
};
function sayDirection(direction){
  switch(direction){
    case Direction.UP :
      console.log('we are going up');
      break;
         case Direction.DOWN :
      console.log('we are going down');
      break;
          case Direction.LEFT :
      console.log('we are going left');
      break;
          case Direction.RIGHT :
      console.log('we are going right');
      break;
  }
};
sayDirection(Direction.UP);
//we are going up

각 케이스별 조건을 걸고 싶은 경우, 

타입스크립트에서 자주 사용함.