Question

I’m trying to find a RegEx that will allow the digits 0-9 ONLY and not special characters. Is this an impossibility since pressing Shift + 2 is still a digit?

I’ve used the following:

return /[0-9]|\./.test(String.fromCharCode(event.keyCode));

Which works fine except for the special characters that are still allowed.

Any input would be most helpful.

Answer 1

I think you are in the right track. Just add !event.shiftKey:

return /[0-9]|\./.test(String.fromCharCode(event.keyCode)) && !event.shiftKey;

There are also altKey and ctrlKey if you need them.

For keyCodes coming form the numeric keypad, you need to compare against the numeric keyCode instead of using a Regex:

return (/[0-9]|\./.test(String.fromCharCode(event.keyCode)) && !event.shiftKey) 
    || (event.keyCode >= 96 && event.keyCode <= 105);

This technique can also be used instead of the Regex you are using:

return (event.keyCode >= 48 && event.keyCode <= 57 && !event.shiftKey) 
    || (event.keyCode >= 96 && event.keyCode <= 105);

See http://unixpapa.com/js/key.html