how to use push in multidimensional array javascript code example

Example 1: how to read 2 dimensional array in javascript

activities.forEach((activity) => {
    activity.forEach((data) => {
        console.log(data);
    });
});

Example 2: multi-dimensional array js

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.