php - after clicking on index.html. The web page you enter is random.

Question

I wrote a program to randomly jump to a web page when clicking on a picture, but I can't write a method to randomly jump to a web page when opening a file directory.
If you don't understand what I mean. You can go and click on my 98 ads. They all have the same link, but the content is different every time you enter. So I would like to ask if it involves back-end knowledge.

Answer 1

1. When the page is loaded for the first time, N links have been obtained, and one is randomly selected when clicked;
2. When clicked, the backend is requested first, and the backend can return a link based on User_Agent and other information. Targeted advertising links;
All roads lead to Rome!
If you are interested in something else, just check the "source code" and see how others have implemented it