e.key up code example

Example: js detect right key click

//detecting arrow key presses - supports both new and depricated methods
document.addEventListener('keydown', function(e) {
	var key = e.key || e.keyCode;
	switch (key) {
		case 'ArrowLeft': case 37:
			alert('left');
			break;
		case 'ArrowUp': case 38:
			alert('up');
			break;
		case 'ArrowRight': case 39:
			alert('right');
			break;
		case 'ArrowDown': case 40:
			alert('down');
			break;
	}
});