这里使用的json解析工具为JSON for Modern C++,使用的话仅需要包含头文件。
获取方式:wget https://github.com/nlohmann/json/releases/download/v3.7.3/json.hpp
JSON
json的序列化功能和map一样,用关联数组的"[]"来任意添加数据,不需要指定数据类型,它会自动推导。添加完之后用dump完成序列化,得到json形式的文本。
#include <iostream>
#include <vector>
#include "json.hpp"
using json_t = nlohmann::json;
int main() {json_t j; // json对象// 添加json对象j["age"] = 21; // "age":23j["name"] = "diyuyi"; // "name":diyuyij["gear"]["suits"] = "2099"; // "gear":{"suits":"2099"}j["jobs"] = {"student"}; // "jobs":["student"]std::vector<int> v = {1, 2, 3};j["numbers"] = v; // "numbers":[1, 2, 3]std::map<std::string, int> m = {{"one", 1},{"two", 2}};j["map"] = m; // "map":{"one", 1},{"two", 2}// 序列化得到json文本形式std::cout << j.dump() << std::endl; // 无缩进std::cout << j.dump(2) << std::endl; // 缩进两格
}
结果:
{"age":21,"gear":{"suits":"2099"},"jobs":["student"],"map":{"one":1,"two":2},"name":"diyuyi","numbers":[1,2,3]}
{"age": 21,"gear": {"suits": "2099"},"jobs": ["student"],"map": {"one": 1,"two": 2},"name": "diyuyi","numbers": [1,2,3]
}
反序列话功能同样简单,调用静态函数parse即可,直接得到json对象
#include <iostream>
#include <vector>
#include "json.hpp"
using json_t = nlohmann::json;
int main() {std::string str = R"({"name":"peter","age":23,"married":true})";json_t j;try {j = json_t::parse(str); // 从字符串反序列化}catch (std::exception& e){std::cout << e.what() << std::endl;}assert(j["age"] == 23); // 验证序列化是否正确
}