#include#include using json = nlohmann::json; int main() { json j = nullptr; std::cout << "Is j null? " << j.isNull() << "\n"; return 0; }
Is j null? 1
#include#include using json = nlohmann::json; int main() { json j = "hello"; std::cout << "Is j null? " << j.isNull() << "\n"; return 0; }
Is j null? 0In this example, we create a `json` value `j` and initialize it with a string `"hello"`. Then, we call the `isNull` method on `j` to check whether it is null or not. As expected, it returns `false` because `j` is not null.