Purpose of index in this solution? (javascript)

function frankenSplice(arr1, arr2, n) {

let localNum = arr2.slice();

localNum.splice(n, 0, ...arr1)

return localNum;


frankenSplice([1, 2, 3], [4, 5, 6], 0);

In this solution I understand just about everything here except for the purpose of n. Why do I need an index of n to copy arr1 into arr2?

Can you post the question link please

According to MDN documentation
let arrDeletedItems = array.splice(start[, deleteCount[, item1[, item2[, ...]]]])

The index at which to start changing the array. This is compulsory argument.

deleteCount Optional

An integer indicating the number of elements in the array to remove from start .
If deleteCount is 0 or negative, no elements are removed. In this case, you should specify at least one new element

item1, item2, ... Optional

The elements to add to the array, beginning from start . If you do not specify any elements, splice() will only remove elements from the array.

Your code has been blurred out to avoid spoiling a full working solution for other campers who may not yet want to see a complete solution. In the future, if you post a full passing solution to a challenge and have questions about it, please surround it with [spoiler] and [/spoiler] tags on the line above and below your solution code.

Thank you.