let n = 15;
let arr = new Array(n).fill(0);
console.log(arr) // [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
let n = 15;
let arr = Array.from(new Array(n), (x, i) => i + 1);
console.log(arr) // [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]
let n = 15;
let arr = Array.from(Array(n).keys());
console.log(arr); // [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14]
let n = 15;
let arr = [...Array(n)].map((x, i) => i);
console.log(arr); // [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14]