protected function _replaceTenPrefixes($string)
    {
        foreach ($this->TEN_PREFIXES as $tp => $tp_replacement) {
            $string = preg_replace_callback(
                "/(?:$tp)( *\d(?=[^\d]|\$))*/i",
                function ($m) use ($tp_replacement) {
                    return $tp_replacement + (isset($m[1]) ? (int)$m[1] : 0);
                },
                $string
            );
        }
        return $string;
    }
protected function _replaceTenPrefixes($string)
    {
        foreach ($this->TEN_PREFIXES as $tp => $tp_replacement) {
            $string = preg_replace_callback(
                "/(?:$tp)( *\d(?=[^\d]|\$))*/i",
                function ($m) use ($tp_replacement) {
                    return $tp_replacement + (isset($m[1]) ? (int)$m[1] : 0);
                },
                $string
            );
        }
        return $string;
    }
protected function _replaceTenPrefixes ( $ string ) { foreach ( $ this -> TEN_PREFIXES as $ tp => $ tp_replacement ) { $ string = preg_replace_callback ( "/(?:$tp)( *\d(?=[^\d]|\$))*/i" , function ( $ m ) use ( $ tp_replacement ) { return $ tp_replacement + ( isset ( $ m [ 1 ] ) ? ( int ) $ m [ 1 ] : 0 ) ; } , $ string ) ; } return $ string ; }
ten, twenty, etc.
ten twenty etc .