实现按字符串的第一个字符的首字母排序

protected function getFirstCharter($str){
        if(empty($str)){return '';}
        $fchar=ord($str{0});
        if($fchar>=ord('A')&&$fchar<=ord('z')) return strtoupper($str{0});
        try{
            $s1=iconv('UTF-8','gb2312',$str);
            $s2=iconv('gb2312','UTF-8',$s1);
        }catch (\Exception $e){
            $s1=iconv('UTF-8','GBK',$str);
            $s2=iconv('GBK','UTF-8',$s1);
        }
        $s=$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 null;
    }
public function index（）{
    $where = array();
     $teacher = D('Teacher')->where($where)->field('id,name')->order('orderval ASC')->select();
        foreach ($teacher as &$value) {
                $value['chart'] = $this->getFirstCharter($value['name']);
            }
            $data=[];
            //给全部数组进行A-Z分类
             foreach ($teacher as $val) {
                if ( empty( $data[ $val['chart'] ] ) ) {
                    $data[$val['chart']]=[];
                }
                $data[$val['chart']][]=$val;
             }
             //按照键名排序
             ksort($data);
             $teacherList=[];
             foreach($data as $k=>$v){
                foreach($v as $item){
                    array_push($teacherList,$item);
                }
            }

        $arrTeacherList = array_column($teacherList,'name','id');//转换成一位数组  id => name  13=>'张三'
}复制代码