How to solve the problem with endless redirects?

Question

PHP

The code:

if($_GET['step'] != "1" || $_GET['step'] != "2" || $_GET['step'] != "3")
{
    header("Location: ?step=1");
}

Problem:

The site * has redirected too many times.

Why?

Answer 1

I solved the problem.
It consisted in the fact that pdo generates data in quotes, that is:
After connecting to the database, it was necessary to cancel such a transformation:
Now everything is working!
Answer that helped me

Answer 2

because the condition in if is always true