Binding arrow keys in JS/jQuery

Question

How do I go about binding a function to left and right arrow keys in Javascript and/or jQuery? I looked at the js-hotkey plugin for jQuery (wraps the built-in bind function

Answer 1

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.

Answer 2

Example of pure js with going right or left

        window.addEventListener('keydown', function (e) {
            // go to the right
            if (e.keyCode == 39) {

            }
            // go to the left
            if (e.keyCode == 37) {

            }
        });

Answer 3

You can use the keyCode of the arrow keys (37, 38, 39 and 40 for left, up, right and down):

$('.selector').keydown(function (e) {
  var arrow = { left: 37, up: 38, right: 39, down: 40 };

  switch (e.which) {
    case arrow.left:
      //..
      break;
    case arrow.up:
      //..
      break;
    case arrow.right:
      //..
      break;
    case arrow.down:
      //..
      break;
  }
});

Check the above example here.

Answer 4

Are you sure jQuery.HotKeys doesn't support the arrow keys? I've messed around with their demo before and observed left, right, up, and down working when I tested it in IE7, Firefox 3.5.2, and Google Chrome 2.0.172...

EDIT: It appears jquery.hotkeys has been relocated to Github: https://github.com/jeresig/jquery.hotkeys

Answer 5

$(document).keydown(function(e){
    if (e.which == 37) { 
       alert("left pressed");
       return false;
    }
});

Character codes:

37 - left

38 - up

39 - right

40 - down

Answer 6

With coffee & Jquery

  $(document).on 'keydown', (e) ->
    switch e.which
      when 37 then console.log('left key')
      when 38 then console.log('up key')
      when 39 then console.log('right key')
      when 40 then console.log('down key')
    e.preventDefault()