Long story short: don't use JSON numbers to represent money or monetary rates. Always use decimals encoded as string. It's surprising how many APIs fall short of this basic bar.
I must admit I totally forgot about the JSON number issue. Our files include fields for various monetary amounts and similar, and in XML we just used "xs:decimal".
Most will be less than a million and requires less than four decimal digits. But I guess someone might decide to use it for the equivalent of a space station or similar, ya never know...
e.g. it doesn't make sense to support billing in sub-currency unit amounts just by allowing it in your API definition, as you're going to need to batch that until you get a billable amount which is larger than the fee for issuing a bill. Even for something like $100,000.1234, the bank doesn't let you do a transfer for 0.34c.
For cases where sub-currency unit billing is a thing, it should be agreed what the minimal unit is (e.g. advertising has largely standardised on millicents)
If you're doing ads and going for millicents, something like $0.01234 should be encoded as 1234 millicents.
Obviously you have to agree on what you're measuring in the API, you can't have some values be millicents and others cents.
https://en.wikipedia.org/wiki/ISO_4217
Or choose a different standard, I don’t know what else is out there, but you probably should choose an existing one.
If you just store cents you can't represent them. You either have to guess at the beginning the smallest unit or store the precision along with it.
Just use strings, it's much simpler.
Encoding numbers as string because you are using a language and parser that can't deal with numbers properly (even 64 bit doubles), is a bit of a hack. Basically the rest of the world giving up because Javascript can't get its shit together is not a great plan.
As the article said
> RFC 8259 raises the important point that ultimately implementations decide what a JSON number is.
Any implementation dealing with money or monetary rates should know that it needs to deal with precision and act accordingly. If you want to use JavaScript to work with money, you need to get a library that allows you to represent high precision numbers. It's not unreasonable to also expect that you get a JSON parsing library that supports the same.
oh, TIL that you can support large numbers with the default JavaScript JSON library https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...