PHP session variable changes between pages

Question

I have a session variable that I set like this:

Answer 1

You will notice that every time you revisit the first page, your session variable will change. Since it works for a constant string, 'example', I will assume that you revisit page 1 to view what is stored there.

A fix could be checking to ensure that that session variable is not set before you set it again. i.e.

This chunk of code should work as expected.