I think something like this should work:
for (var i=0;i==0 || +Pin(i);i++) print(new Pin(i))
But the easiest thing is just to look at the pinout page for the board: http://www.espruino.com/Pixl.js#pinout
@Gordon started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I think something like this should work:
But the easiest thing is just to look at the pinout page for the board: http://www.espruino.com/Pixl.js#pinout