Question

Is it possible to use switch in coffeescript without break?

switch code                      switch (code) {
    when 37 then                     case 37: break;
    when 38 then           ->        case 38: break;
    when 39 then                     case 39: break;
    when 40                          case 40:
        ...                              ...

I thought this will work but failed:

switch code
    when 37 then continue
    when 38 then continue  ->    not valid
    when 39 then continue
    when 40
        ...

Answer 1

Not really. From the docs:

Switch statements in JavaScript are a bit awkward. You need to remember to break at the end of every case statement to avoid accidentally falling through to the default case. CoffeeScript prevents accidental fall-through, and can convert the switch into a returnable, assignable expression. The format is: switch condition, when clauses, else the default case.

What you can do, though, is specify several values in a case, if they are to be treated equally:

switch day
  when "Mon" then go work
  when "Tue" then go relax
  when "Thu" then go iceFishing
  when "Fri", "Sat"
    if day is bingoDay
      go bingo
      go dancing
  when "Sun" then go church
  else go work