Is it possible to keep track of a random character in swift?

I created a project and I added that swipe gesture thing, my ViewController has a label when I swipe left👈 It replaces my label with random string from my array (It works ok),However when I swipe right👉 I want to see the previous string from my array the problem is that it is a random string so I can’t keep track of it, any ideas how to do it?