php获取汉字首字母实例

在我们实际开发工作中，有时候需要获取输入汉字的首字母，然后存到库中，方便用户搜索相关信息，下面给出php代码，留做备用：

//新添加获取汉子首字，首字字母

    function pinyin($zh){

           if(empty($zh)){

                      return '';

               }

           $s1 = iconv("UTF-8","gb2312", $zh);

           $s2 = iconv("gb2312","UTF-8", $s1);//将字符串的编码从GB2312转到UTF-8

           if($s2 == $zh){$zh = $s1;}

           $s1 = substr($zh,0,1);

           $p = ord($s1);

           if($p > 160){

               $s2   = substr($zh,0,2);

               return strtoupper(self::getfirstchar($s2));

           }else{

               return strtoupper($s1);

           }

    }

    function getfirstchar($s0){

           $fchar = ord($s0{0});

           if($fchar >= ord("A") and $fchar <= ord("z") )return strtoupper($s0{0});

           $s1 = self::get_encoding($s0,'GB2312');

           $s2 = self::get_encoding($s1,'UTF-8');

           if($s2 == $s0){$s = $s1;}else{$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";

           return null;

   }