Get the uppercase initials of Chinese Pinyin in PHP

Preface

In the project of project development, I encountered the function of returning a string of Chinese strings to uppercase initials , After learning from the methods of other developers on the Internet, I sorted out the best method .

Problem description

Need to put 【 Downstream rockfill area 】 convert to 【XYDSQ】.

Method example

    if (!function_exists('getfirstchar')) {
    
        /** *  Get the capital first letter of Chinese Pinyin  * @param [type] $str * @return void */
        function getfirstchar($str)
        {
    
            $fchar = ord(substr((string) $str, 0, 1));
            if (($fchar >= ord("a") and $fchar <= ord("z")) or ($fchar >= ord("A") and $fchar <= ord("Z"))) {
    
                return strtoupper(chr($fchar));
            }

            $s = iconv("UTF-8", "GBK", (string) $str);
            $asc = ord($s{
    0}) * 256 + ord($s{
    1}) - 65536;
            if ($asc >= -20319 and $asc <= -20284) {
    
                return "A";
            }

            if ($asc >= -20283 and $asc <= -19776) {
    
                return "B";
            }

            if ($asc >= -19775 and $asc <= -19219) {
    
                return "C";
            }

            if ($asc >= -19218 and $asc <= -18711) {
    
                return "D";
            }

            if ($asc >= -18710 and $asc <= -18527) {
    
                return "E";
            }

            if ($asc >= -18526 and $asc <= -18240) {
    
                return "F";
            }

            if ($asc >= -18239 and $asc <= -17923) {
    
                return "G";
            }

            if ($asc >= -17922 and $asc <= -17418) {
    
                return "H";
            }

            if ($asc >= -17417 and $asc <= -16475) {
    
                return "J";
            }

            if ($asc >= -16474 and $asc <= -16213) {
    
                return "K";
            }

            if ($asc >= -16212 and $asc <= -15641) {
    
                return "L";
            }

            if ($asc >= -15640 and $asc <= -15166) {
    
                return "M";
            }

            if ($asc >= -15165 and $asc <= -14923) {
    
                return "N";
            }

            if ($asc >= -14922 and $asc <= -14915) {
    
                return "O";
            }

            if ($asc >= -14914 and $asc <= -14631) {
    
                return "P";
            }

            if ($asc >= -14630 and $asc <= -14150) {
    
                return "Q";
            }

            if ($asc >= -14149 and $asc <= -14091) {
    
                return "R";
            }

            if ($asc >= -14090 and $asc <= -13319) {
    
                return "S";
            }

            if ($asc >= -13318 and $asc <= -12839) {
    
                return "T";
            }

            if ($asc >= -12838 and $asc <= -12557) {
    
                return "W";
            }

            if ($asc >= -12556 and $asc <= -11848) {
    
                return "X";
            }

            if ($asc >= -11847 and $asc <= -11056) {
    
                return "Y";
            }

            if ($asc >= -11055 and $asc <= -10247) {
    
                return "Z";
            }
            return null;
        }
    }

    if (!function_exists('get_letter')) {
    
        /** *  Get the capital first letter of Chinese Pinyin  * @param [type] $string * @return void */
        function get_letter($string)
        {
    
            $charlist = preg_split('/(?<!^)(?!$)/u', (string) $string);
            return implode(array_map("getfirstchar", $charlist));
        }
    }

Usage method

//【 Downstream rockfill area 】 convert to 【XYDSQ】
$zone_name_pinyin = get_letter(' Downstream rockfill area ');