I don't quite know what you mean by "rely on" here, but the isEmpty fields are implemented on the iterator interface, so any of the standard container types imp

I don't quite know what you mean by "rely on" here, but the isEmpty fields are implemented on the iterator interface, so any of the standard container types implement it by default, including lists, sets, and maps. Also to address other posts in the thread, while I don't think this specific example is worth indicting JS developers over, I do think the culture of infinite dependencies common to JS developers is. This shouldn't be an entire additional dependency. Just implement the modulo operation, or as parent suggests, make a nicely named utility function that wraps the modulo operation. But when the culture strongly encourages downloading micro packages for every little thing, I can hardly blame them for adding this into the pile of yet more things they've downloaded.