Weird syntax error after creating a new project in laravel 5

I created a new project: laravel new myprojectname and I am getting a blank page. First, I thought is about the permission so I gave the 777 to the storage folder, but I still had the blank page. Then I checked the logs and I saw this:

    production.ERROR: Parse error: syntax error, unexpected '?', expecting 
variable (T_VARIABLE) {"exception":"[object] (Symfony\\Component\\Debug
\\Exception\\FatalThrowableError(code: 0): Parse error: syntax error, 
unexpected '?', expecting variable (T_VARIABLE) at /opt/lampp/htdocs
/myprojectname/vendor/symfony/routing/Route.php:53)  .....

My php version is: 7.1.14 . Does anyone know why I get this ?

Thank you

via Chebli Mohamed