CodeIgniter 2.2.0 Not compatiable with PHP 7.2?

I have website develop by someone using CodeIgniter 2.2.0 , It working fine . 

But when I update PHP from 5.6 to 7.2 error happens. I locate /system/core/CodeIgniter.php

 Error happen on  $CI = new $class();

I am new on CodeIgniter. So what new $class() do . And how to solve this problem .

Thanks.

It's not compatible, you need to upgrade to at least CodeIgneter 3 for PHP 7.2 support.