PHP实现汉字或英文按照首字母查找

/**
    *
    */
function getfirstchar($s0){
               if($s0[0]=='I' || $s[0]=='i'){
                   return "I";
               }elseif($s0[0]=='U' || $s[0]=='u'){
                   return 'U';
               }elseif($s0[0]=='V' || $s[0]=='v'){
                   return 'V';
               }else{
    $fchar = ord($s0{0});
    if($fchar >= ord("A") and $fchar     $s1 = iconv("UTF-8","gb2312", $s0);
    $s2 = iconv("gb2312","UTF-8", $s1);
    if($s2 == $s0){$s = $s1;}else{$s = $s0;}
    $asc = ord($s{0}) * 256 + ord($s小贝) - 65536;
    if($asc >= -20319 and $asc     if($asc >= -20283 and $asc     if($asc >= -19775 and $asc     if($asc >= -19218 and $asc     if($asc >= -18710 and $asc     if($asc >= -18526 and $asc     if($asc >= -18239 and $asc     if($asc >= -17922 and $asc     if($asc >= -17417 and $asc     if($asc >= -16474 and $asc     if($asc >= -16212 and $asc     if($asc >= -15640 and $asc     if($asc >= -15165 and $asc     if($asc >= -14922 and $asc     if($asc >= -14914 and $asc     if($asc >= -14630 and $asc     if($asc >= -14149 and $asc     if($asc >= -14090 and $asc     if($asc >= -13318 and $asc     if($asc >= -12838 and $asc     if($asc >= -12556 and $asc     if($asc >= -11847 and $asc     if($asc >= -11055 and $asc     return null;
               }
    }

首字母, PHP