The fourth outlet of the
key and
keyup objects output a
keyboard-independent code you can use to detect key presses and releases
as described below.
When pressing a letter or number key,
the values reported from this outlet correspond to the
unshifted Unicode (ASCII) valuversion of the pressed key.
When pressing a key that is a character key but is not a letter or number,
the Unicode value of the key symbol that would be output by the keyboard
when the shift key is not depressed is output.
(For example, on U.S. keyboards,
there is a key with both a single and double quote.
When this key is pressed, the key object will report single quote.
Other keys such as function, home, page up etc. output a consistent values independent of
keyboard on each platform. The values are listed below: