How to Convert a Map to a JSON String in C++ - Step by Step Examples

How to Convert a Map to a JSON String in C++ ?

Answer

To convert a map to a JSON string in C++, you can use a JSON library such as nlohmann/json. This library provides an easy way to convert standard containers, including maps, to JSON strings.

✐ Examples

1 Converting a std::map to a JSON String

We can convert a std::map to a JSON string in C++ using the nlohmann/json library, which provides a convenient way to work with JSON data.

For example,

We start by including the nlohmann/json header file.
We declare and initialize a std::map named myMap with key-value pairs.
We create a JSON object from the map using the nlohmann::json constructor.
We convert the JSON object to a string using the dump method.
We print the resulting JSON string to the console using std::cout.

C++ Program

#include <iostream>
#include <map>
#include <nlohmann/json.hpp>

int main() {
    // Declare and initialize a std::map
    std::map<int, int> myMap = {
        {1, 10},
        {2, 20},
        {3, 30},
        {4, 40},
        {5, 50}
    };

    // Create a JSON object from the map
    nlohmann::json jsonObj = myMap;

    // Convert the JSON object to a string
    std::string jsonString = jsonObj.dump();

    // Print the resulting JSON string
    std::cout << "JSON string from map: " << jsonString << std::endl;

    return 0;
}

Output

JSON string from map: {"1":10,"2":20,"3":30,"4":40,"5":50}

Summary

In this tutorial, we learned How to Convert a Map to a JSON String in C++ language with well detailed examples.

◀ Previous Next ▶

C++ Tutorials

C++ How-Tos