I have never seen this used, but my friend just told me that instead of writing:
var x = 1;
var y = 2;
var z = 3;
you can, and should, write:
var x = 1,
y = 2,
z = 3;
Never seen or heard of this, and not sure how it works, but I tried it on jsfiddle and it seems to work fine..?