Access Multi-Dimensional Arrays With Indexes
One way to think of a multi-dimensional
array, is as an array of arrays. When you use brackets to access your array, the first set of bracket refers to the entries in the outer-most array, and each subsequent level of brackets refers to the next level of entries inside.
Example
var arr = [
[1,2,3],
[4,5,6],
[7,8,9],
[[10,11,12], 13, 14]
];
arr[0]; // equals [1,2,3]
arr[1][2]; // equals 6
arr[3][0][1]; // equals 11