basic_json::iterator::value() output includes quotes while basic_json::iterator::key() doesn't

[RElesgoe]

I've noticed that when iterating through a json object, calling value() wraps the string with quotes while key() doesn't. This should be changed so that either they both be wrapped with quotes or not wrapped at all.

[nlohmann]

Thanks for reporting! I'll check!

[nlohmann]

This is not a bug.

key() returns a std::string and value() returns a basic_json object. So the former gives you they key as it was stored, whereas the latter gives you a JSON serialization of the string. This includes escaping characters, see RFC 7159.

So if you want an escaped version of the key, you need to create a JSON value out of it first.

Example:

#include <json.hpp>

using nlohmann::json;

int main()
{
    json s = "\"quoted\"";
    json j = {{s, s}};

    std::cout << "output of j (json): " << j << "\n";
    std::cout << "output of the first key (std::string): " << j.begin().key() << "\n";
    std::cout << "output of the first key (json): " << json(j.begin().key()) << "\n";
    std::cout << "output of the first value (json): " << j.begin().value() << "\n";
    std::cout << "output of the first value (std::string): " << j.begin()->get<std::string>() << "\n";
}

Output:

output of j (json): {"\"quoted\"":"\"quoted\""}
output of the first key (std::string): "quoted"
output of the first key (json): "\"quoted\""
output of the first value (json): "\"quoted\""
output of the first value (std::string): "quoted"