Weird javascript thing


I have a code snippet with javascript integrated jQuery

the code snippet:

ul.children().outerWidth(function(i, w) {

the w is used in another section += w;

I try to understand all my code so now that function i is not understand for what is for? if removed the script is stoped working???

Any idea what is that? and why is that if not listened one more time to use it and if remove not work hmmm

Can you provide a link to your code, so we can understand the full context of your code?