Question

My code is

$('input').live('keypress', function(event) {
   if (event.keyCode === 37) console.log("left key pressed");
    else console.log("some other key press");
});

Please see http://jsfiddle.net/4RKeV/

This detects keypresses, but not the left keypress (keyCode 37). How can I detect left keypress?

Answer 1

In short: don’t use the keypress event. Use keydown or keyup instead.

The keypress event is not covered by any official specification. As such, keypress does not have well-defined behavior, will not work the same way across browsers, and will act capriciously and unpredictably. (Read more ^{[quirksmode.org]})

As an alternative to keypress, you should use one of these events:

• keydown ^{[w3c spec]} — This triggers when a key is pressed down and continues to trigger while the key is held down.
• keyup ^{[w3c spec]} — This triggers when the key is lifted up.

I would probably fix it by using keydown because it is probably closer to what you were expecting keypress to do:

$('input').live('keydown', function(e) { 
   if (e.which === 37) { console.log("left key pressed"); }
   else { console.log("some other key press"); }
}); 

---

P.S. I changed e.keyCode to e.which, because it is more cross-browser compliant.