PHP obtains the first letter of a Chinese/English string.

PHP obtains the first letter of a Chinese/English string.

Use Cases: When filtering regions, we often see filtering and locating by English letters. At first we thought it was too troublesome to relate the areas stored in the data table to the first letter, then I want to get the first letter based on the region name and then group the region. The following method is used:

function getFirstCharter($str) {    if (empty($str)) {        return '';    }    $fchar = ord($str{0});    if ($fchar >= ord('A') && $fchar <= ord('z')) return strtoupper($str{0});    $s1 = iconv('UTF-8', 'gb2312', $str);    $s2 = iconv('gb2312', 'UTF-8', $s1);    $s = $s2 == $str ? $s1 : $str;    $asc = ord($s{0}) * 256 + ord($s{1}) - 65536;    if ($asc >= -20319 && $asc <= -20284) return 'A';    if ($asc >= -20283 && $asc <= -19776) return 'B';    if ($asc >= -19775 && $asc <= -19219) return 'C';    if ($asc >= -19218 && $asc <= -18711) return 'D';    if ($asc >= -18710 && $asc <= -18527) return 'E';    if ($asc >= -18526 && $asc <= -18240) return 'F';    if ($asc >= -18239 && $asc <= -17923) return 'G';    if ($asc >= -17922 && $asc <= -17418) return 'H';    if ($asc >= -17417 && $asc <= -16475) return 'J';    if ($asc >= -16474 && $asc <= -16213) return 'K';    if ($asc >= -16212 && $asc <= -15641) return 'L';    if ($asc >= -15640 && $asc <= -15166) return 'M';    if ($asc >= -15165 && $asc <= -14923) return 'N';    if ($asc >= -14922 && $asc <= -14915) return 'O';    if ($asc >= -14914 && $asc <= -14631) return 'P';    if ($asc >= -14630 && $asc <= -14150) return 'Q';    if ($asc >= -14149 && $asc <= -14091) return 'R';    if ($asc >= -14090 && $asc <= -13319) return 'S';    if ($asc >= -13318 && $asc <= -12839) return 'T';    if ($asc >= -12838 && $asc <= -12557) return 'W';    if ($asc >= -12556 && $asc <= -11848) return 'X';    if ($asc >= -11847 && $asc <= -11056) return 'Y';    if ($asc >= -11055 && $asc <= -10247) return 'Z';    return null;}

BY bjr 15:00:45