99% of times a `switch` statement is a BAD idea

BAD.php

<?php

$preferences = [ 'c', 'e' ];
$params      = [];

foreach ($preferences as $setting)
{
	switch($setting)
	{
		case 'a':
			$params[] = "-ie -ff -ch";
			break;
		case 'b':
			$params[] = "true";
			break;
		case 'c':
			$params[] = "-mtb";
			break;
		case 'd':
			$params[] = "-mds";
			break;
		case 'e':
			$params[] = "-mhp -mnt";
			break;
	}
}

GOOD.php

<?php

$preferences = [ 'c', 'e' ];

$flags = [
	'a' => '-ie -ff -ch',
	'b' => 'true',
	'c' => '-mtb',
	'd' => '-mds',
	'e' => '-mhp -mnt',
];

// Returns an array containing all the entries of `flags`
// which have keys that are present in `preferences`.
// Preferences values are flipped for key intersection.
$params = array_intersect_key($flags, array_flip($preferences));