Questions about converting Chinese characters into pinyin

The problem of converting Chinese characters into pinyin is that I want to bring up the first letter of Chinese characters. I found this function on the internet. However, it is depressing that many of the less commonly used Chinese characters cannot be identified, for example, sequence, sinus, sequence... and so on. I don't know how to solve this problem. PHPcodefunctiongetfirstchar ($ s0) {$ firstchar_ordord (strtoupper ($ s0 {0}); if ($ f Chinese character conversion problem)
I want to bring up the first letter of a Chinese character and search for the following function on the Internet. However, what is depressing is that many of the less commonly used Chinese characters cannot be identified, such as Yi, Dou, Yi... and so on. I don't know how to solve this problem.

PHP code

  function getfirstchar($s0){         $firstchar_ord=ord(strtoupper($s0{0}));         if (($firstchar_ord>=65 and $firstchar_ord<=91)or($firstchar_ord>=48 and $firstchar_ord<=57)) return $s0{0};         $s0=iconv("UTF-8","gb2312", $s0);        $s=$s0;         $asc=ord($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";     } 

------ Solution --------------------
Your table is too small to cover only 3775 Chinese characters.

You can use this http://blog.csdn.net/xuzuning/article/details/5060835
------ Solution --------------------
Deep understanding ~~