php 7.1无法识别php5.6+语法'use函数`

答案是禁用模块php 5并为apache启用7.1:

sudo a2dismod php5
sudo a2enmod php7.1
sudo service apache2 restart

use keywork will support all version of php. i think your function declaration error. 
you can use below example and correct your function
**use** can only be used with anonymous functions. Using it with named functions 
 gives a syntax error.

 <?
function counter($start) {
  $value = $start;

 return function() use (&$value) {
   return $value++;
 };

}

 $counter = counter(6);

echo $counter() . "\n";
echo $counter() . "\n";