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Is it possible to generate enum from <String> array in Swift?

Here's my listing:

enum myEnum : Int {
    case apple = 0
    case orange
    case lemon
}

I would like to create it from an array. Array elements can be the name of enumerations.

let myEnumDictionary : Array<String> = ["apple","orange","lemon"]

So, is it possible to create enums from an array?

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2 answers


No, It is Immpossible. Similarly, you cannot create classes from arrays.



The enumerations must be compiled. You cannot create them dynamically.

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If your enum rawValue

needs to be Int, you can either map from an array of integer raw values ​​to a collection of enumerations, or add a convenience initializer that returns an enumeration that matches the given string literal:

enum MyEnum : Int {
    case apple = 0
    case orange
    case lemon

    init?(fruit: String) {
        switch fruit {
        case "apple":
            self = .apple
        case "orange":
            self = .orange
        case "lemon":
            self = .lemon
        default:
            return nil
        }
    }
}

let myEnumDictionary = [0, 1, 2].map{ MyEnum(rawValue: $0) }.flatMap{ $0 }

let myEnumDictionary2 = ["apple", "orange", "lemon"].map{ MyEnum(fruit: $0) }.flatMap{ $0 }

If the enum type rawValue

was a string, you wouldn't need to provide an initializer:



enum MyEnum: String {
    case apple
    case orange
    case lemon
}

let myEnumDictionary = ["apple", "orange", "lemon"].map{ MyEnum(rawValue: $0) }.flatMap{ $0 }

Of course, the easiest way to create an array of enums is to simply provide a list of lists of enums:

let myEnumDictionary: [MyEnum] = [.apple, .orange, .lemon]
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