Demo showing the danger of using PHP's include statement

include.php

<?php

$variable = 'include';

return $variable;

php-include-demo.php

<?php

$includeFunction = function($file) { return include $file; };

$variable = 'original';
$config = include "include.php";

var_dump($variable, $config); // include, include

$variable = 'original';
$config = $includeFunction("include.php");

var_dump($variable, $config); // original, include

$variable = 'original';
$config = [
    'uhm' => include "include.php",
];

var_dump($variable, $config); // include, [uhm] => include, 

$variable = 'original';
$config = [
    'uhm' => $includeFunction("include.php"),
];

var_dump($variable, $config); // original, [uhm] => include