@swift-ci create

Comment by Kyle Macomber (JIRA)

I can't reproduce on my Mac:

import Foundation

struct Foo: Codable {
 var decimal: Decimal
}

let json = "\{ \"decimal\": 1.43 }".data(using: .utf8)!

let decoder = JSONDecoder()
let foo = try decoder.decode(Foo.self, from: json)

print(foo.decimal) // Prints "1.43" on Darwin

Perhaps this is specific to corelibs-foundation?

Comment by Pabitra Ranjan Sahu (JIRA)

@kyla Macomber, I can see this is not reproducible but when I am trying to parse JSON from API response, then I can see this.

Please look into this Github reproducible link here:-

SwiftyJSON/SwiftyJSON#930

Comment by Kyle Macomber (JIRA)

It's my understanding that JSON does not have first class support for decimal numbers and the best practice is to encode decimal numbers as Strings rather than Doubles in JSON.

It appears the issue against SwiftyJSON you linked to was closed for this reason.

Comment by Mattt (JIRA)

kylemacomber (JIRA User) - My understanding is that JSON specifies only the representation of numbers, not how any particular implementation interprets them. If that's indeed the case, any practice of encoding decimal values as strings is a workaround for mistakes or limitations in those implementations. (Granted, JSON parsing is a minefield, so what passes as "correct behavior" is debatable).

Comment by Mattt (JIRA)

Quick follow-up: Here's a reproducible example:

import Foundation
struct Foo: Codable { 
  var decimal: Decimal 
}
let json = "{ \"decimal\": 27.31 }".data(using: .utf8)!
let decoder = JSONDecoder() 
let foo = try decoder.decode(Foo.self, from: json)
print(foo.decimal) // Prints "27.30999999999999488" on macOS

Comment by Kyle Macomber (JIRA)

I see, that makes sense. Re-opening.

Comment by Adriano Gonçalves (JIRA)

Isn't this issue a duplicate of rdar://problem/33491336 ?