首先我们要确定要保存json文件的格式，只有事先确定json文件的格式，才能构造它。

{
   "age" : 24,
   "array" : [
      {
         "cancel" : "取消",
         "loginfail" : "登录失败",
         "loginsuccess" : "登录成功",
         "ok" : "确定"
      },
      {
         "cancel" : "取消",
         "loginfail" : "登录失败",
         "loginsuccess" : "登录成功",
         "ok" : "确定"
      },
      {
         "cancel" : "取消",
         "loginfail" : "登录失败",
         "loginsuccess" : "登录成功",
         "ok" : "确定"
      }
   ],
   "name" : "HaKing"
}

void writeJson()
{
    std::string filePath = "/Users/Fsy/Desktop/C++/Json/king.json";
    std::ofstream fout;
    fout.open(filePath.c_str());
    assert(fout.is_open());

    Json::Value root;        // 根节点
    root["name"] = "HaKing"; // 根节点下"name"对应的值"HaKing"
    root["age"] = 24;        // 根节点下"age"对应的值24

    Json::Value array;   // 创建数组
    for (int i = 0; i < 3; i++)
    {
        Json::Value item;
        item["ok"] = "确定";
        item["cancel"] = "取消";
        item["loginsuccess"] = "登录成功";
        item["loginfail"] = "登录失败";
        array.append(item); // append()以数组的形式添加
    }
    root["array"]= array;
    std::string out = root.toStyledString();
    std::cout << out << std::endl;
    fout << out << std::endl;
}