PHP 7 Syntax error, question mark before specifying the parameter

Question

I developed a website on Laravel using the version PHP 7.2, when I climbed to the server (that is using version 7.0 of PHP) I noticed that I was giving a syntax error in the following line

public function __construct(?string $test)

This line belongs to a standard file of the Laravel

Here is the complete error:

mod_fcgid: stderr: PHP Parse error: syntax error, unexpected '?', expecting variable (T_VARIABLE) in /var/www/vhosts/placarama.com.br/httpdocs/vendor/symfony/finder/Comparator/NumberComparator.php on line 42

Along with him is another mistake

mod_fcgid: stderr: PHP Fatal error: Exception thrown without a stack frame in Unknown on line 0

Does anyone have any idea what it might be?

Answer 1

The version does not match the new feature called Nullable types which has been introduced in the version 7.1, then the 7.0 does not have this feature so of the mistakes.

_{Reference: Nullable types - PHP Version 7.1}