array_unique with two arrays

Question

I have two arrays of the same length ($search_type, $search_term). I want to remove any duplicates in the sense of there being searches that have the same type and

Answer 1

It doesn't look like there's a simple way to solve the problem using just built-in functions.

This (at least logically) should work.

$search_terms = array('a', 'b', 'c', 'c', 'd', 'd');
$search_types = array( 1,   2,   3,   4,   5,   5);

$terms = array_fill_keys($search_terms, array());
// Loop through them once and make an array of types for each term
foreach ($search_terms as $i => $term)
    $terms[$term][] = $search_types[$i];

// Now we have $terms = array('a' => array(1),
//                            'b' => array(2),
//                            'c' => array(3, 4),
//                            'd' => array(5, 5)
//                      );

// Now run through the array again and get rid of duplicates.
foreach ($terms as $i => $types)
    $terms[$i] = array_unique($types);

Edit: Here's a shorter and presumably more efficient one where you end up with a less pretty array:

$search_terms = array('a', 'b', 'c', 'c', 'd', 'd');
$search_types = array( 1,   2,   3,   4,   5,   5);

$terms = array_fill_keys($search_terms, array());
// Loop through them once and make an array of types for each term
foreach ($search_terms as $i => $term)
    $terms[$term][$search_types[$i]] = 1;

// Now we have $terms = array('a' => array(1 => 1),
//                            'b' => array(2 => 1),
//                            'c' => array(3 => 1, 4 => 1),
//                            'd' => array(5 => 1)
//                      );