Console.log a multi-dimensional array

You can use javascript's console.table

This will display your array in table form, making it much more readable and easy to analyse
It is quite a little known feature, however useful when you have a multi-dimentional array.

So, change your code to console.table(items);
It should give you something like this:

 -----------------------
|(index)|   0   |   1   |
|   0   |   1   |   2   |
|   1   |   3   |   4   |
|   2   |   5   |   6   |
 -----------------------

You can use JSON.stringify()

console.log(JSON.stringify(items));

Its output will be like

[[1,2],[3,4],[5,6]]

var items = [[1,2],[3,4],[5,6]];
console.log(JSON.stringify(items));