Use `isEmpty` for Iterables and MapsDRT-W1147
DON'T use length
to see if a collection is empty.
The Iterable
contract does not require that a collection know its length or be
able to provide it in constant time. Calling length
just to see if the
collection contains anything can be painfully slow.
Instead, there are faster and more readable getters: isEmpty
and
isNotEmpty
. Use the one that doesn't require you to negate the result.
BAD:
if (lunchBox.length == 0) return 'so hungry...';
if (words.length != 0) return words.join(' ');
GOOD:
if (lunchBox.isEmpty) return 'so hungry...';
if (words.isNotEmpty) return words.join(' ');