1 #include <iostream>
2 #include <iomanip>
3 #include <nlohmann/json.hpp>
4
5 using json = nlohmann::json;
6
main()7 int main()
8 {
9 // create a JSON object
10 json j =
11 {
12 {"pi", 3.141},
13 {"happy", true},
14 {"name", "Niels"},
15 {"nothing", nullptr},
16 {
17 "answer", {
18 {"everything", 42}
19 }
20 },
21 {"list", {1, 0, 2}},
22 {
23 "object", {
24 {"currency", "USD"},
25 {"value", 42.99}
26 }
27 }
28 };
29
30 // add new values
31 j["new"]["key"]["value"] = {"another", "list"};
32
33 // count elements
34 auto s = j.size();
35 j["size"] = s;
36
37 // pretty print with indent of 4 spaces
38 std::cout << std::setw(4) << j << '\n';
39 }
40