How to pass variables between php scripts?

Question

Is there any way to pass values and variables between php scripts?

Formally, I tried to code a login page and when user enter wrong input first another script will

Answer 1

I use extract() method to pass variable among PHP Scripts. It look like below example:

1. File index.php

'hello',
    'content'=>'hello world'
];
extract($data);
require 'content.php';

2. File content.php :