Hello Reader's If you want to get all elements in the combinations then you can use PHP code to generate it.
Lets see the example as below:-

function pc_permute($items, $perms = array()) {
    if (empty($items)) { 
        echo join(' ', $perms) . "<br />";
    } else {
        for ($i = count($items) - 1; $i >= 0; --$i) {
             $newitems = $items;
             $newperms = $perms;
             list($foo) = array_splice($newitems, $i, 1);
             array_unshift($newperms, $foo);
             pc_permute($newitems, $newperms);
         }
    }
}

The array is:-

$arr = array('peter', 'paul', 'mary');

pc_permute($arr);

Output:-

peter-paul-mary
peter-mary-paul
paul-peter-mary
paul-mary-peter
mary-peter-paul
mary-paul-peter