最近查看的Cookie数组 - 需要从数组和上限cookie中提取数据到5个ID

I am trying to create a recently viewed feature to a website. The idea is that you have a box in the right nav that shows your last 3 products viewed. You don't need to be logged it and it's no problem if the user clears cookies, it just starts over.I am trying to create a recently viewed feature