JSFiddle - React, Tailwind, and code Playground
JavaScript
var array1 = [[1, 1, 0],
[0, 1, 0],
[2, 0, 1]];
alert(array1[0][0]+array1[1][1]+array1[2][2]);
alert(array1[0][0]+array1[0][1]+array1[0][2]);
alert(array1[0][0]+array1[1][0]+array1[2][0]);