two dimensional array javascript code example

Example 1: js array two dimensional

// declaration of a two-dimensional array
// 5 is the number of rows and 4 is the number of columns.
const matrix = new Array(5).fill(0).map(() => new Array(4).fill(0));

console.log(matrix[0][0]); // 0

Example 2: n dimensional array js

// 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)]

Example 3: how to read 2 dimensional array in javascript

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

Example 4: creating a 2d array in js

var x = new Array(10);

for (var i = 0; i < x.length; i++) {
  x[i] = new Array(3);
}

console.log(x);

Example 5: 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.

Example 6: javascript fill 2 dimensional array

const fillSquareMatrix = (size) => {
  return Array(size)
    .fill()
    .map((u,y) => Array(size)
         .fill()
         .map((u,x) => y * size + x + 1));
};

console.log(fillSquareMatrix(3));