up down left right keycode events

u-d-l-r.js

document.addEventListener('keyup', function (e) {
  	var keyCode = e.keyCode || e.which,
	arrow = { left: 37, up: 38, right: 39, down: 40 };

	switch (keyCode) {
		case arrow.left:
			console.log(keyCode);
		break;
		
		case arrow.up:
			console.log(keyCode);
		break;
		
		case arrow.right:
			console.log(keyCode);
		break;
		
		case arrow.down:
			console.log(keyCode);
		break;
	}

});