lesson on class variables is incorrect.

[michaelglass]

putting attributes on the prototype does not use more memory than putting it on the constructor function.

[iainbeeston]

It might be worth explaining the difference between defining a constant on the prototype vs on the constructor. As it is I find it confusing which one is the "correct" way of defining a class variable (I'm thinking maybe on the prototype would be better, but I haven't really thought about the pros and cons)

[michaelglass]

I think I tried to make the difference clear. Either way: existing cookbook entry is dead wrong.

[iainbeeston]

But I the discussion at the bottom only applies to the @constructor style class method, but not the prototype style. Although it doesn't explicitly say which it is talking about.

[michaelglass]

line 26? there's some usage of prototype. Wanna take a stab at it?

I'm not sure what lives in the realm of "this is coffeescript" vs "this is javascript"

[peterhellberg]

I’m happy to accept this pull request, we can improve the explanation over time. @iainbeeston Are you cool with that?

[iainbeeston]

Sure that's fine.

[peterhellberg]

@michaelglass I’ve now added you to the contributors team, welcome 🎉