ADS1115 analog gain signal module - how to run it with espruino?

thank you Gordon, it is working now, espruino is reading all channels and gain is working as well,
I can now move on and try to finish my project ;)

do you know the way how to create new var value which will get readings from this ADS function?

ads.getADC(0, function(val0) {});

I have to do plenty of mathematical operations with my variable on few channels, it would be much simpler to use eg. var inputOne instead of this function above,
actually I can't print val0 outside the function, and I need to use readings from ADS in few steps, make a math and then print it,
I appreciate help in this case