Copy part of an array with slice()

To copy part of an array:

• arr.slice([begin, end)
• arr.slice(begin)

It returns a new array filled with items from arr.

begin is 0-based index of the first item.

end is 0-based index of the last item

If only begin is given, slice copies everything until the end of array

If end is negative it becomes end = arr.length + end i.e. -1 would leave off last element of array, -2 last 2 elements etc.

if end is ≤ begin, returns an empty array.

const arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];

let newArr = arr.slice(0, 2);
console.log("slice(0,2)  :", newArr)

newArr = arr.slice(8);
console.log("slice(8)    :", newArr)

newArr = arr.slice(5, -1);
console.log("slice(5, -1):", newArr)

newArr = arr.slice(6, -2);
console.log("slice(6, -2):", newArr)

newArr = arr.slice(3, 3)
console.log("slice(3, 3) :", newArr)

newArr = arr.slice(4, 1)
console.log("slice(4, 1) :", newArr)

slice(0,2)  : [ 0, 1 ]
slice(8)    : [ 8, 9 ]
slice(5, -1): [ 5, 6, 7, 8 ]
slice(6, -2): [ 6, 7 ]
slice(3, 3) : []
slice(4, 1) : []