Filter out elements of a flat array which do not contain all search terms

We have an array, for example:

$my_array = array(
    'Software Engineering',
    'Civil Engineering',
    'Hardware Engineering',
    'BL AH Engineering'
);

Now I have a "$q" variable, I want to search between values of the array, remove the keys which doesn't contain $q, here is my code:

foreach ($my_array as $key => &$value) {
    if (stripos(($value), $q) === false) {
        unset($my_array[$key]);
    }
}

now if we set the $q = 'eer':

var_dump($my_array);
array
  0 => string 'Software Engineering' (length=20)
  1 => string 'Civil Engineering' (length=17)
  2 => string 'Hardware Engineering' (length=20)
  3 => &string 'BL AH Engineering' (length=17)

as you see, nothing is removed since all the $values have 'eer' in 'Engineering' it's OK, but now I set $q = 'eer civil', now:

var_dump($my_array);
array
  empty

All the items are removed, but actually the 'Civil Engineering' contains both the 'eer' and 'civil', so it should not be removed, how I could make this work? I may explode the $q with ' space ' but it's not working.

Using explode should work:

Update

Use preg_split and trim to get rid of multiple/leading/trailing delimiters.

$array = array('Software Engineering', 'Civil Engineering', 'Hardware Engineering', 'BL AH Engineering');
$query = ' eer   civil ';
$query = preg_split('/\s+/', trim($query));
foreach ($array as $key => $value) {
    foreach ($query as $q) {
        if (stripos($value, $q) === false) {
            unset($array[$key]);
            break;
        }
    }
}
var_dump($array);

http://codepad.org/r3jJX1aP