jQuery Forum

{} and [] both have a length, where as NULL does not.the error makes sense, however what should it do instead in a case where null undefined is passed into the each?

This is really a question of how much we should sanity check bad inputs, and what we should do when garbage is passed in. A null doesn't make sense as an argument to $.each. Since the first arg should be an object or array, users can just say $.each(myPossiblyNullVar || [], fn)to avoid the error and make it clear to readers that the arg could be null or undefined. This seems like a benefit, I'd prefer to read that code.