php汉字生成首字母

function getfirstchar($s0){
    $fchar = ord($s0{});
    if($fchar >= ord("A") and $fchar <= ord("z") )return strtoupper($s0{});
    $s1 = iconv("UTF-8","gb2312", $s0);
    $s2 = iconv("gb2312","UTF-8", $s1);
    if($s2 == $s0){$s = $s1;}else{$s = $s0;}
    $asc = ord($s{}) *  + ord($s{}) - ;
    if($asc >= - and $asc <= -) return "A";
    if($asc >= - and $asc <= -) return "B";
    if($asc >= - and $asc <= -) return "C";
    if($asc >= - and $asc <= -) return "D";
    if($asc >= - and $asc <= -) return "E";
    if($asc >= - and $asc <= -) return "F";
    if($asc >= - and $asc <= -) return "G";
    if($asc >= - and $asc <= -) return "I";
    if($asc >= - and $asc <= -) return "J";
    if($asc >= - and $asc <= -) return "K";
    if($asc >= - and $asc <= -) return "L";
    if($asc >= - and $asc <= -) return "M";
    if($asc >= - and $asc <= -) return "N";
    if($asc >= - and $asc <= -) return "O";
    if($asc >= - and $asc <= -) return "P";
    if($asc >= - and $asc <= -) return "Q";
    if($asc >= - and $asc <= -) return "R";
    if($asc >= - and $asc <= -) return "S";
    if($asc >= - and $asc <= -) return "T";
    if($asc >= - and $asc <= -) return "W";
    if($asc >= - and $asc <= -) return "X";
    if($asc >= - and $asc <= -) return "Y";
    if($asc >= - and $asc <= -) return "Z";
    return null;
}

function pinyin1($zh){
    $ret = "";
    $s1 = iconv("UTF-8","gb2312", $zh);
    $s2 = iconv("gb2312","UTF-8", $s1);
    if($s2 == $zh){$zh = $s1;}
    for($i = ; $i < strlen($zh); $i++){
        $s1 = substr($zh,$i,);
        $p = ord($s1);
        if($p > ){
            $s2 = substr($zh,$i++,);
            $ret .= getfirstchar($s2);
        }else{
            $ret .= $s1;
        }
    }
    return $ret;
}
echo "这是中文字符串<br/>";
echo pinyin1('这是中文字符串');