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;
   }