title: Javascript function that converts array to array of "2-tuples"
body: <p>How do I write a javascript function that takes an array as its input <code>[0, 1, 2, 3, 4, 5, 6, 7, 8]</code> and returns <code>[ [0, 1], [2, 3], [4, 5], [6, 7], [8] ]</code>?</p>