http_build_query with same name parameters

Here is a function I created to build the query and preserve names. I created this to work with a third-party API that requires multiple query string parameters with the same name.

function custom_build_query($query_data) {
    $query = array();
    foreach ($query_data as $name => $value) {
        $value = (array) $value;
        array_walk_recursive($value, function($value) use (&$query, $name) {
            $query[] = urlencode($name) . '=' . urlencode($value);
        });
    }
    return implode("&", $query);
}

Usage:

echo custom_build_query(['a' => 1, 'b' => 2, 'c' => [3, 4]]);

Outputs:

a=1&b=2&c=3&c=4

This should do what you want, I had an api that required the same thing.

$vars = array('foo' => array('x','y'));
$query = http_build_query($vars, null, '&');
$string = preg_replace('/%5B(?:[0-9]|[1-9][0-9]+)%5D=/', '=', $query); //foo=x&foo=y