История изменений

for (var i in obj.foo.bar) xxx(obj.foo.bar[i].blah);

var i, bar = obj.foo.bar;
for (i in bar) {
    xxx(bar[i].blah);
}

for (var i in obj.foo.bar) xxx(obj.foo.bar[i].blah);

var i, barItem;
for (i in obj.foo.bar) {
    barItem = obj.foo.bar[i];
    xxx(barItem.blah);
}