[PHP知识库]PHP省市区按字母分组

/**
 * Describe: 地区列表
 */
public function regionList()
    {
        $type = input('post.type');//列表类型：1普通列表，2按字母分组列表
        $level = input('post.level');
        $pid = input('post.pid');
        $fields = "id,name,parent_id as parentId,level";
        if ($level == 1) {//省份
            $list = Db::name('region')->where(['level' => 1])->field($fields)->select();
        } elseif ($level == 2) {//城市
            $list = Db::name('region')->where(['level' => 2, 'parent_id' => $pid])->field($fields)->select();
        } elseif ($level == 3) {//区域
            $list = Db::name('region')->where(['level' => 3, 'parent_id' => $pid])->field($fields)->select();
        }
        if ($type == 1) {
            $res = $list;
        } elseif ($type == 2) {
            $res = $this->groupByFirstCharters($list);
        }

        returnJson(0, 'msg', $res);
    }

    public function groupByFirstCharters($data, $targetKey = 'name')
    {
        $data = array_map(function ($item) use ($targetKey) {
            return array_merge($item, [
                'initials' => $this->getFirstCharters($item[$targetKey]),
            ]);
        }, $data);
        $data = $this->sortFirstCharters($data);
        return $data;
    }

    public function getFirstCharters($str)
    {
        if (empty($str)) {
            return '';
        }
        if ($str == "衢州市") {
            return 'Q';
        } elseif ($str == "亳州市") {
            return 'B';
        } elseif ($str == "濮阳市") {
            return 'P';
        } elseif ($str == "漯河市") {
            return 'L';
        } elseif ($str == "儋州市") {
            return 'D';
        } elseif ($str == "泸州市") {
            return 'L';
        } elseif ($str == "重庆城区") {
            return 'C';
        } elseif ($str == "重庆郊县") {
            return 'C';
        }


        $fchar = ord($str[
        0]);

        if ($fchar >= ord('A') && $fchar <= ord('z')) {
            return strtoupper($str[
            0]);
        }

        $s1 = iconv('UTF-8', 'gbk//TRANSLIT//IGNORE', $str);
        $s2 = iconv('gbk//TRANSLIT//IGNORE', '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 && $asc <= -10247) {
            return 'Z';
        }
        if ($asc > -11055) {
            return '#';
        }

        return null;
    }

    public function sortFirstCharters(array $data)
    {
        $sortData = [];
        foreach ($data as $key => $value) {
            $sortData[$value['initials']][] = $value;
        }
        ksort($sortData);
        return $sortData;
    }