Swift enum with a custom constructor

Question

I have a simple enum of type string:

enum MyEnum: String {
    case hello = "hello"
    case world = "world"
}

And I want to write a case-insensitive constructor. I tried this (with or without extension):

init?(string: String) {
    return self.init(rawValue: string.lowercased())
}

but I get an error saying:

'nil' is the only value permitted in an initializer

Alexander · Accepted Answer · 2018-12-11 19:18:48Z

3

You don't need to return anything. You just call initializer:

enum MyEnum: String {
    case hello = "hello"
    case world = "world"

    init?(caseInsensitive string: String) {
        self.init(rawValue: string.lowercased())
    }
}

print(MyEnum(caseInsensitive: "HELLO") as Any) // => Optional(Untitled.MyEnum.hello)
print(MyEnum(caseInsensitive: "Goodbye") as Any) // => nil

edited Dec 11, 2018 at 19:18

answered Dec 11, 2018 at 17:45

Alexander

63.9k13 gold badges106 silver badges177 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Swift enum with a custom constructor

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related