shuffle.js

let shuffle = function(array) {
	for (var c = array.length - 1; c > 1; c--) {
		var r = (Math.random() * c).toFixed(0);
		var one = array[r];
		var two = array[c];

		if (one !== null) {
			array[c] = one;
			array[r] = two;
		}
	}

	return array;
};