src/Net/URL2.php
private function _queryArrayByKey($key, $value, array $array = array())
    {
        if (!strlen($key)) {
            return $array;
        }

        $offset = $this->_queryKeyBracketOffset($key);
        if ($offset === false) {
            $name = $key;
        } else {
            $name = substr($key, 0, $offset);
        }

        if (!strlen($name)) {
            return $array;
        }

        if (!$offset) {
            // named value
            $array[$name] = $value;
        } else {
            // array
            $brackets = substr($key, $offset);
            if (!isset($array[$name])) {
                $array[$name] = null;
            }
            $array[$name] = $this->_queryArrayByBrackets(
                $brackets, $value, $array[$name]
            );
        }

        return $array;
    }
private function _queryArrayByKey($key, $value, array $array = array())
    {
        if (!strlen($key)) {
            return $array;
        }

        $offset = $this->_queryKeyBracketOffset($key);
        if ($offset === false) {
            $name = $key;
        } else {
            $name = substr($key, 0, $offset);
        }

        if (!strlen($name)) {
            return $array;
        }

        if (!$offset) {
            // named value
            $array[$name] = $value;
        } else {
            // array
            $brackets = substr($key, $offset);
            if (!isset($array[$name])) {
                $array[$name] = null;
            }
            $array[$name] = $this->_queryArrayByBrackets(
                $brackets, $value, $array[$name]
            );
        }

        return $array;
    }
Parse a single query key=value pair into an existing php array

@param string $key   query-key
@param string $value query-value
@param array  $array of existing query variables (if any)

@return mixed