Answer 1

There is no way to get input for PHP code in Code Playground, that is because PHP was created for web back-end programming, back-end codes do not interact with users, front-end codes does that, the front-end code gets user inputs and send them for the back-end code to process.

Given that, all we could do was only to forge a request data in $_POST or $_GET, or create a variable for the code to work with.