Filling multidimensional arrays in JavaScript

Suppose now we want to create some multidimensional array with numbers in a loop. For example, here is a two-dimensional array:

javascript[[1, 2, 3], [1, 2, 3], [1, 2, 3]]

Let's solve the problem by using two nested loops. The outer loop will create sub-arrays and the inner loop will fill these sub-arrays with numbers:

javascriptlet arr = [];

for (let i = 0; i < 3; i++) {
  arr[i] = []; // create a subarray
  
  for (let j = 0; j < 3; j++) {
    arr[i].push(j + 1); // fill the subarray with numbers
  }
}

console.log(arr);

javascript[[1, 2, 3, 4, 5], [1, 2, 3, 4, 5], [1, 2, 3, 4, 5]]

javascript[
  ['x', 'x', 'x', 'x'],
  ['x', 'x', 'x', 'x'],
  ['x', 'x', 'x', 'x']
]

javascript[
  [
    [1, 2, 3, 4, 5],
    [1, 2, 3, 4, 5],
  ],
  [
    [1, 2, 3, 4, 5],
    [1, 2, 3, 4, 5],
  ],
  [
    [1, 2, 3, 4, 5],
    [1, 2, 3, 4, 5],
  ],
]