因项目需要用到此功能，于是在网上找到一份代码，记录下来，也让后来者有个参考。
//获取汉字的首字母 function getFirstCharters($str) { if (empty($str)) { return ''; } //取出参数字符串中的首个字符 $temp_str = substr($str,0,1); if(ord($temp_str) > 127){ $str = substr($str,0,3); }else{ $str = $temp_str; $fchar = ord($str{0}); if ($fchar >= ord('A') && $fchar <= ord('z')){ return strtoupper($temp_str); }else{ return null; } } $s1 = iconv('UTF-8', 'gb2312//IGNORE', $str); if(empty($s1)){ return null; } $s2 = iconv('gb2312', 'UTF-8', $s1); if(empty($s2)){ return null; } $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 && $asc <= -10247) return 'Z'; return rare_words($asc); } //百家姓中的生僻字 function rare_words($asc=''){ $rare_arr = array( -3652=>array('word'=>"窦",'first_char'=>'D'), -8503=>array('word'=>"奚",'first_char'=>'X'), -9286=>array('word'=>"酆",'first_char'=>'F'), -7761=>array('word'=>"岑",'first_char'=>'C'), -5128=>array('word'=>"滕",'first_char'=>'T'), -9479=>array('word'=>"邬",'first_char'=>'W'), -5456=>array('word'=>"臧",'first_char'=>'Z'), -7223=>array('word'=>"闵",'first_char'=>'M'), -2877=>array('word'=>"裘",'first_char'=>'Q'), -6191=>array('word'=>"缪",'first_char'=>'M'), -5414=>array('word'=>"贲",'first_char'=>'B'), -4102=>array('word'=>"嵇",'first_char'=>'J'), -8969=>array('word'=>"荀",'first_char'=>'X'), -4938=>array('word'=>"於",'first_char'=>'Y'), -9017=>array('word'=>"芮",'first_char'=>'R'), -2848=>array('word'=>"羿",'first_char'=>'Y'), -9477=>array('word'=>"邴",'first_char'=>'B'), -9485=>array('word'=>"隗",'first_char'=>'K'), -6731=>array('word'=>"宓",'first_char'=>'M'), -9299=>array('word'=>"郗",'first_char'=>'X'), -5905=>array('word'=>"栾",'first_char'=>'L'), -4393=>array('word'=>"钭",'first_char'=>'T'), -9300=>array('word'=>"郜",'first_char'=>'G'), -8706=>array('word'=>"蔺",'first_char'=>'L'), -3613=>array('word'=>"胥",'first_char'=>'X'), -8777=>array('word'=>"莘",'first_char'=>'S'), -6708=>array('word'=>"逄",'first_char'=>'P'), -9302=>array('word'=>"郦",'first_char'=>'L'), -5965=>array('word'=>"璩",'first_char'=>'Q'), -6745=>array('word'=>"濮",'first_char'=>'P'), -4888=>array('word'=>"扈",'first_char'=>'H'), -9309=>array('word'=>"郏",'first_char'=>'J'), -5428=>array('word'=>"晏",'first_char'=>'Y'), -2849=>array('word'=>"暨",'first_char'=>'J'), -7206=>array('word'=>"阙",'first_char'=>'Q'), -4945=>array('word'=>"殳",'first_char'=>'S'), -9753=>array('word'=>"夔",'first_char'=>'K'), -10041=>array('word'=>"厍",'first_char'=>'S'), -5429=>array('word'=>"晁",'first_char'=>'C'), -2396=>array('word'=>"訾",'first_char'=>'Z'), -7205=>array('word'=>"阚",'first_char'=>'K'), -10049=>array('word'=>"乜",'first_char'=>'N'), -10015=>array('word'=>"蒯",'first_char'=>'K'), -3133=>array('word'=>"竺",'first_char'=>'Z'), -6698=>array('word'=>"逯",'first_char'=>'L'), -9799=>array('word'=>"俟",'first_char'=>'Q'), -6749=>array('word'=>"澹",'first_char'=>'T'), -7220=>array('word'=>"闾",'first_char'=>'L'), -10047=>array('word'=>"亓",'first_char'=>'Q'), -10005=>array('word'=>"仉",'first_char'=>'Z'), -3417=>array('word'=>"颛",'first_char'=>'Z'), -6431=>array('word'=>"驷",'first_char'=>'S'), -7226=>array('word'=>"闫",'first_char'=>'Y'), -9293=>array('word'=>"鄢",'first_char'=>'Y'), -6205=>array('word'=>"缑",'first_char'=>'G'), -9764=>array('word'=>"佘",'first_char'=>'S'), -9818=>array('word'=>"佴",'first_char'=>'N'), -9509=>array('word'=>"谯",'first_char'=>'Q'), -3122=>array('word'=>"笪",'first_char'=>'D'), -9823=>array('word'=>"佟",'first_char'=>'T'), ); if(array_key_exists($asc, $rare_arr) && $rare_arr[$asc]['first_char']){ return $rare_arr[$asc]['first_char'] ; }else{ return null; } }