n dimensional array js

                                    //2D array
let activities = [
    ['Work', 9],
    ['Eat', 1],
    ['Commute', 2],
    ['Play Game', 1],
    ['Sleep', 7]
];

                                    var grid = [];
iMax = 3;
jMax = 2;
count = 0;

    for (let i = 0; i < iMax; i++) {
      grid[i] = [];

      for (let j = 0; j < jMax; j++) {
        grid[i][j] = count;
        count++;
      }
    }

// grid = [
//   [ 0, 1 ]
//   [ 2, 3 ]
//   [ 4, 5 ]
// ];

console.log(grid[0][2]); // 4

                                    /*having the previous array easy to make is very useful*/

function Array2D(x, y){
 let arr = Array(x);
  for(let i = 0; i < y; i++){
   arr[i] = Array(y);
  }
  return arr;
}

function Array3D(x, y, z){
 let arr = Array2D(x, y);
      for(let i = 0; i < y; i++){
       for(let j = 0; j < z; j++){
        arr[i][j] = Array(z);
       }
      }
  return arr;
}

function Array4D(x, y, z, w){
 let arr = Array3D(x, y, z);
      for(let i = 0; i < x; i++){
       for(let j = 0; j < y; j++){
        for(let n = 0; n < z; n++){
        arr[i][j][n] = Array(w);
       }
       }
      }
  return arr;
}
/*making the array*/
let myArray = Array4D(10, 10, 10, 10);

                                    var array = [
  ["0, 0", "1, 0", "2, 0", "3, 0", "4, 0"],
  ["0, 1", "1, 1", "2, 1", "3, 1", "4, 1"],
  ["0, 2", "1, 2", "2, 2", "3, 2", "4, 2"],
  ["0, 3", "1, 3", "2, 3", "3, 3", "4, 3"],
  ["0, 4", "1, 4", "2, 4", "3, 4", "4, 4"],
  ]; // Think of it as coordinates, array[x, y] x = 0; y = 0; is "0, 0" on 
	// this grid

console.log(array[3][3]); // returns "3, 3"
// If you use graphics (ex: p5js or JS Canvas) then this will be a 5x5 map.
// Useful for roguelikes and/or raycasters.

                                    // function to create a n-dimentional array
function createArray(length) {
    var arr = new Array(length || 0),
        i = length;

    if (arguments.length > 1) {
        var args = Array.prototype.slice.call(arguments, 1);
        while(i--) arr[length-1 - i] = createArray.apply(this, args);
    }

    return arr;
}

//eg.
createArray();     // [] or new Array()

createArray(2);    // new Array(2)

createArray(3, 2); // [new Array(2),
                   //  new Array(2),
                   //  new Array(2)]