Swift version: 5.6
Most Swift developers use camel case for naming properties, which means we start with a lowercase letter then capitalize the first letter of second and subsequent words: numberOfUsers
or powerLevel
. On the other hand, many web APIs prefer snake case, written as number_of_users
and power_level
, so if you need to convert camel case to snake case you need to use the keyEncodingStrategy
of JSONEncoder
, like this:
let encoder = JSONEncoder()
encoder.keyEncodingStrategy = .convertToSnakeCase
if let encoded = try? encoder.encode(yourData) {
// continue with encoded data
}
With that set, Swift can convert property names as part of the encoding process, which makes Codable
much easier to use.
A similar property exists on JSONDecoder
, except now it’s called keyDecodingStrategy
. It does the same thing in reverse: specifying .convertFromSnakeCase
will convert names_like_this
into namesLikeThis
.
SPONSORED An iOS conference hosted in Buenos Aires, Argentina – join us for the third edition from November 29th to December 1st!
Sponsor Hacking with Swift and reach the world's largest Swift community!
Available from iOS 8.0
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
Link copied to your pasteboard.