Emotional Damage!!!

Nope. You are allowed to use String.prototype.length, and people would just use array["len"+"gth"], leading to a war of attrition that can't be won.

Because it is quite impossible to disable [].length, and because filtering for "length" is an iffy proposition at best,
THIS KATA WORKS ON THE HONOUR SYSTEM.

If you want free points, you can have 'em. Note I wrote this kata in a Christmas break ( in an hour ). :D

@JohanWiltnik uh... you didn't check for the keyword length??? :P