That's not only wrong in itself, but totally orthogonal. A binary search implementation should still work, regardless of the array length, or have the limitati

That's not only wrong in itself, but totally orthogonal. A binary search implementation should still work, regardless of the array length, or have the limitation documented. And of course an array "with length over a billion" can be totally valid, depending on the use case, your tradeoffs, available memory, etc. It could even be the optimal data structure for some use cases.