Setting values of .JSON file

[takeyourwingsback]

This is example of my .JSON file.
{"Settings":{"AutoReload":true,"CheckingUpdates":false}}
What function should I use to set the value of "Settings-AutoReload" from "True" to "False", for example? To set and save it.

[nlohmann]

Assume your JSON file is called file.json, then you can read it with

std::ifstream input_file("file.json");
json j;
input_file >> j;

Then you can access the value with operator[]:

j["Settings"]["AutoReload"] = false;

[takeyourwingsback]

Assume your JSON file is called file.json, then you can read it with

std::ifstream input_file("file.json");
json j;
input_file >> j;

Then you can access the value with operator[]:

j["Settings"]["AutoReload"] = false;

Okay. But question is about can I rewrite and save JSON file with the new value? Or I can work only with gotten value, can't set it?
I need to set only value of ["Settings"]["AutoReload"] and with new value rewrite JSON file. Is that possible like in INI ?

[nlohmann]

Do you mean how to write a JSON value (like j in the example) to a file? Have a look at https://github.com/nlohmann/json#serialization--deserialization

[takeyourwingsback]

Do you mean how to write a JSON value (like j in the example) to a file? Have a look at https://github.com/nlohmann/json#serialization--deserialization

Yes, but only this value. Other values should not be changed if user didn't set them. Only needed value should be rewrited in JSON file.

[nlohmann]

I do not understand. How should the expected JSON file look like?

[takeyourwingsback]

I do not understand. How should the expected JSON file look like?

I'm sorry. For example, this's current JSON file
{"Settings":{"AutoReload":true,"CheckingUpdates":false}}

The user wanna set the value of "Settings - AutoReload", set it from "True" to "False" and save it by rewriting JSON file with the new value. The new JSON file will look like
{"Settings":{"AutoReload":false,"CheckingUpdates":false}}

As you can see, other value of "Settings - CheckingUpdates" was not touched, because user didn't set it. In short - can I work and rewrite only a specific value? Can I rewrite the file, changed "Settings - AutoReload" value to "True" and didn't touched "Settings - CheckingUpdates" value ? Or should I use INI or something another for this purpose?

[nlohmann]

So you want to write the complete changed value j.

// read
std::ifstream input_file("file.json");
json j;
input_file >> j;

// change
j["Settings"]["AutoReload"] = false;

// write
std::ofstream output_file("new_file.json");
j >> output_file;

The content of that file should be

{"Settings":{"AutoReload":false,"CheckingUpdates":false}}

[takeyourwingsback]

So you want to write the complete changed value j.

// read
std::ifstream input_file("file.json");
json j;
input_file >> j;

// change
j["Settings"]["AutoReload"] = false;

// write
std::ofstream output_file("new_file.json");
j >> output_file;

The content of that file should be

{"Settings":{"AutoReload":false,"CheckingUpdates":false}}

Thank you very much.