Random Integer lower bound

[smaspe]

in http://coffeescriptcookbook.com/chapters/math/random-integer
there is this

if not lower?
  [lower, upper] = [0, lower]

If lower does not exist, how can it be considered to use it as upper value?

(I considered using [0, upper], but since upper is after lower in the arguments, It would have its default value anyway. Number.MAX_VALUE, may be?)

[sukima]

By using the lower variable you can use this function with one argument. It's a bit cryptic. A better way to write it might be:

randomInt = (lower, upper) ->
  [lower, upper] = [0, lower]     unless upper?           # Called with one argument
  [lower, upper] = [upper, lower] if lower > upper        # Lower must be less then upper
  Math.floor(Math.random() * (upper - lower + 1) + lower) # Last statement is a return value

randomInt(3, 15) # => between 3 and 15
randomInt(15, 3) # => between 3 and 15
randomInt(5)     # => between 0 and 5

[sukima]

@njzk2 I apologize. I realized that I mis-read your issue. I though you were asking a different question. You were right checking for lower was a typo which was fixed by commit b9752d8.