[joebadmo]

Yes, there's a note right after:

    Note that this trick should only be used
    for arrays which you know do not contain 
    "falsy" values (arrays of objects or DOM 
    nodes for example). If you are iterating 
    over numeric data that might include a 0 
    or string data that might include the 
    empty string you should use the i, len 
    idiom instead.