How to complete this code?one filling is required.

Question

const arr1 = [1, 2, 3];
const arr2 = [5, 6, 7, 8];
let arr3 = [ arr1,4, ...arr2];

Answer 1

I dont know what you actually want but by just analyse your code I think its just another simple spread operator so you will get a new array from 1 to 8.