It will be useful if it can access not just last but also the length - k item with arr.at(-k). For example arr.at(-3). If it's just for the last one, it won't be that good.
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It will be useful if it can access not just last but also the length - k item with arr.at(-k). For example arr.at(-3). If it's just for the last one, it won't be that good.
Yes, any negative index works.