When combining assignment with comma (something that you shouldn't do, probably), how does javascript determine which value is assigned? Consider these two snippets:
function nl(x) { document.write(x + "<br>"); }
var i = 0;
nl(i+=1, i+=1, i+=1, i+=1);
nl(i);
And:
function nl(x) { document.write(x + "<br>"); }
var i = 0;
nl((i+=1, i+=1, i+=1, i+=1));
nl(i);
The first outputs
1
4
while the second outputs
4
4
What are the parentheses doing here?