javascript two dimensional array

                                    var iMax = 20;
var jMax = 10;
var f = new Array();

for (i=0;i<iMax;i++) {
 f[i]=new Array();
 for (j=0;j<jMax;j++) {
  f[i][j]=0;
 }
}

                                    /*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);

                                    // 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)]

                                    let data = [];
for (let row=0; row<rows; row++) {
    data.push(new Array(cols).fill('#'));
};

                                    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