Implementing an identical JSON.stringify

[Claude Pache]

> Le 5 août 2018 à 00:16, Michael Theriot <michael.lee.theriot at gmail.com> a écrit :
> 
> `JSON.stringify` has unintuitive behavior regarding interal slots.

I don’t think that anything involving an object that has a [[StringData]] internal slot but has `Number.prototype` in its prototype chain could have an ”intuitive” behaviour...

> 
> 
> I think this is related to `Array.isArray`. Is there an equivalent `Number.isNumber`? Or is this just something only `JSON.stringify` can do?

Try `Number.prototype.valueOf.call(obj)`: it will throw a TypeError if and only if `obj` has no [[NumberData]] internal slot. Ditto for String, Boolean and Symbol.

—Claude