关于nlohmann::json的简单使用

#include "json.hpp"
#include <iostream>
using Info = nlohmann::json;
int main()
{
  Info info;
  std::cout << info.size() << std::endl;
  info["a"] = "b";
  std::cout << info["a"] << std::endl;
  auto iter = info.find("a");
  if (iter == info.end()) {
    std::cout << "not found" << std::endl;
  }
  else {
    std::cout << *iter << std::endl;
  }
  std::string s = R"({
    "name" : "nick",
    "credits" : "123",
    "ranking" : 1
  })";
  auto j = nlohmann::json::parse(s);
  std::cout << j["name"] << std::endl;
  std::string ss = j.dump();
  std::cout << "ss : " << ss << std::endl;
  Info j1;
  Info j2 = nlohmann::json::object();
  Info j3 = nlohmann::json::array();
  std::cout << j1.is_object() << std::endl;
  std::cout << j1.type_name() << std::endl;
  std::cout << j2.is_object() << std::endl;
  std::cout << j2.is_array() << std::endl;
  Info infoo{
    {"name", "darren"},
    {"credits", 123},
    {"ranking", 1}
  };
  std::cout << infoo["name"] << std::endl;
  std::cout << infoo.type_name() << std::endl;
  //遍历
  for (auto iter = infoo.begin(); iter != infoo.end(); iter++) {
    std::cout << iter.key() << " : " << iter.value() << std::endl;
    //std::cout << iter.value() << std::endl;
    //std::cout << *iter << std::endl;
  }
  system("pause");
  return 0;
}

std::vector<std::pair<std::string, int>> keyValuePairs;
  keyValuePairs.emplace_back("key3", 3);
  keyValuePairs.emplace_back("key1", 1);
  keyValuePairs.emplace_back("key2", 2);
  nlohmann::json jsonObject(keyValuePairs);
  // 输出序列化后的JSON数据
  std::cout << jsonObject.dump() << std::endl;
  std::cout << "===============" << std::endl;
  nlohmann::ordered_json orderjson;
  orderjson["a"] = 1;
  orderjson["c"] = 2;
  orderjson["b"] = 3;
  std::cout << orderjson.dump(2) << std::endl;