document.onkeydown = function(e) {
switch(e.which) {
case 37: // left
break;
case 38: // up
break;
case 39: // right
break;
case 40: // down
break;
default: return; // exit this handler for other keys
}
e.preventDefault(); // prevent the default action (scroll / move caret)
};
If you need to support IE8, start the function body as e = e || window.event; switch(e.which || e.keyCode) {
.
(edit 2020)
Note that KeyboardEvent.which
is now deprecated. See this example using KeyboardEvent.key
for a more modern solution to detect arrow keys.