JSON.stringify and JSON.parse? They're standard library functions that many languages have, I don't see what's ES6 about them, they're much older. First class

JSON.stringify and JSON.parse? They're standard library functions that many languages have, I don't see what's ES6 about them, they're much older. First class treatment would be if the language had JSON-typed objects with functionality, e.g. something like const myJson = j'{"key":"value"}'; const value = myJson['key']; const newJson = myJson.set("otherkey", "newValue"); (using the j'' notation for a hypothetical json-typed value) But AFAIK it doesn't, not even in ES6.