Вывод алфавитов в один массив

function printAlphabet($from = 192, $to = 223) {
    $tmp = [];
    $range = range($from, $to);
    foreach($range as $letter) {
        $tmp[] = iconv('CP1251', 'UTF-8', chr($letter));
    }
    return $tmp;
}


$arResult['LETTERS'] = array_merge(printAlphabet(),printAlphabet(65,90));