javascriptOff-by-oneMedium

Off-by-one when slicing the last N items

Time: 0:00

What it should do

getLastNItems(arr, n) should return the last n items of arr, e.g. getLastNItems([1,2,3,4,5], 2) -> [4, 5].

What goes wrong

getLastNItems([1,2,3,4,5], 2) returns [3, 4, 5] — one extra item at the front.

Hints

This is an off-by-one errors bug

The loop that runs one time too many, the slice that drops the last item, the index that starts in the wrong place.