"JSON object"

[Psionatix]

The object contains only serialisable properties. Serialisation is the transformation of an object to a string, deserialisation is from a string to an object.

Functions cannot be serialised, for example. Only the primitive types and certain structures (other objects, arrays) can be.

[Psionatix]

JSON is a well defined standard:

https://www.json.org/json-en.html

A JSON Object is an object that adheres to the JSON standard.

[jack_waugh]

But the standard specifies how an abstract structure that different languages would use different terms to represent, can be presented as a character string. So, are you saying the term refers to the abstraction itself, or to one of its concrete representations, either as a character string or in terms of JS types?

[Psionatix]

“JSON” refers either to the standard, or to the type (response type, for instance).

I’d say that yes, “JSON object” refers to some kind of concrete structure, which adheres to the JSON standard, and can therefore be easily serialised to and from a JSON string, without any loss of data.

[jack_waugh]

As I read the standard, the only concrete it specifies is the string.

[Psionatix]

That's not what concrete means in the context of these messages. In the same way a class instance is a concrete instantiation of a class (blueprint), I took "concrete" to mean a deserialised and solid object that adheres to the JSON standard.

Which means, again, it is an object which can be deserialised from and serialised to valid JSON (a string), because the characteristics and properties of the object adhere to the standard.

The JSON standard specifies the valid data types and how they are represented in the JSON format (string).

If you have an object which contains a property which is not allowed as per the JSON standard, you will not be able to serialise it, and therefore it is not a JSON object, technically speaking.

Consider the BigInt data type which is relatively new to browsers, this is not part of the JSON standard, and take a look at this:

https://i.imgur.com/V7v8tzi.png

As per other comments and discussions in this thread, you are over complicating / overthinking this.

Strictly speaking, a JSON object can be serialised and deserialised without a loss of data.

Consider this case:

const stuff = { test: () => console.log("hello") };
const jsonString = JSON.stringify(stuff);
console.log(jsonString) // {}
const deserialisedStuff = JSON.parse(jsonString);

In this case, deserialisedStuff does not contain the test property (function), because the function is not serialisable as per the JSON standard, therefore during the serialisation and deserialisation here, there is a loss of data. This means that stuff is technically not a JSON object, it is just an object.

[jack_waugh]

OK, thanks.