How do you disable all keys with jQuery except backspace?

Question

I can successfully stop all keys from being pressed with:

$this.keydown(false);

How can I disable all keys with the exception of the backspace key?

Answer 1

Check the keyCode of the event argument:

$this.keydown(function(e) {
    if(e.keyCode !== 8) {
        e.preventDefault();
    }
});

Here's a demo.

Answer 2

Use a callback, check the keycode of the pressed key, if it's the backspace key then allow it, otherwise block.