coffeescript check if not in array

Here's something simple to check if user is in moderator. But I want to check if user is not in moderator.

if err && user in moderators
  return

Intuitively it would be like this

if err && user isnt in moderators
  return

But obviously this doesn't work. What's the best way to do it?

Solution 1:

isnt is the opposite of is, which is the triple equals sign. Just negate the in:

if err and user not in moderators
  return

or, using postfix if:

return if err and user not in moderators

In CoffeeScript, NOT can be denoted as ! or not

if err && !(user in moderators)

if err && user not in moderators

would both work.