OC- 字典套数组 -- 省市区

// 获取文件
NSString *str = [NSString stringWithContentsOfFile:@"area.txt" encoding:NSUTF8StringEncoding error:nil];
// 按\n截取
NSArray *line = [str componentsSeparatedByString:@"\n"];
// 新建空省数组
NSMutableArray *proArr = [NSMutableArray array];
//
for (NSString *lineStr in line) {
    // 省
    if (![lineStr hasPrefix:@"  "]) {
        // 新建市数组
        NSMutableArray *citArr = [NSMutableArray array];
        // 省字典
        NSMutableDictionary *proDic = [NSMutableDictionary dictionaryWithObjectsAndKeys:lineStr, @"provinceName", citArr, @"cit", nil];
        [proArr addObject:proDic];
    }   else if (![lineStr hasPrefix:@"    "]) {
        // 市
        // 新建区数组
        NSMutableArray *areaArr = [NSMutableArray array];
        // 新建市字典
        NSMutableDictionary *citDic = [NSMutableDictionary dictionaryWithObjectsAndKeys:lineStr, @"cityName", areaArr, @"area", nil];
        // 获取市所属的省字典
        NSMutableDictionary *proDic = proArr.lastObject;
        // 获取市所属的市数组
        NSMutableArray *citArr = [proDic objectForKey:@"cit"];
        // 将建好的市子典添加到市数组中
        [citArr addObject:citDic];
    }   else {
        // 区
        // 获取区所属的省字典
        NSMutableDictionary *proDic = proArr.lastObject;
        // 获取区所属的市数组
        NSMutableArray *citArr = [proDic objectForKey:@"cit"];
        // 获取区所属的市字典
        NSMutableDictionary *citDic = citArr.lastObject;
        // 获取区所属的区数组
        NSMutableArray *areaArr = [citDic objectForKey:@"area"];
        // 将区名直接添加到区数组中
        [areaArr addObject:lineStr];
    }
}
// 转换为控制台看见中文字符
NSData *data = [NSJSONSerialization dataWithJSONObject:proArr options:NSJSONWritingPrettyPrinted error:nil];
NSString *contentStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@", contentStr);