As of Swift 4.2 (Xcode 10) you can declare conformance to the CaseIterable protocol, this works for all enumerations without associated values: enum Stuff: CaseIterable { case first case second case third case forth } The number of cases is now simply obtained with print(Stuff.allCases.count) // 4 For more information, see SE-0194 Derived Collection of … Read more
You are printing the enum object. Use the .value attribute if you wanted just to print that: print(D.x.value) See the Programmatic access to enumeration members and their attributes section: If you have an enum member and need its name or value: >>> >>> member = Color.red >>> member.name ‘red’ >>> member.value 1 You could add … Read more
Here’s one example (a similar/better one is found in Effective Java 2nd Edition): public interface Operator { int apply (int a, int b); } public enum SimpleOperators implements Operator { PLUS { int apply(int a, int b) { return a + b; } }, MINUS { int apply(int a, int b) { return a – … Read more
You can either use the “?” operator for a nullable type. public Color? myColor = null; Or use the standard practice for enums that cannot be null by having the FIRST value in the enum (aka 0) be the default value. For example in a case of color None. public Color myColor = Color.None;
Enums in Java (and probably enums in general) should be singular. The thinking is that you’re not selecting multiple Protocols, but rather one Protocol of the possible choices in the list of values. Note the absence of plurals: http://docs.oracle.com/javase/tutorial/java/javaOO/enum.html
Check out Enum.IsDefined Usage: if(Enum.IsDefined(typeof(MyEnum), value)) MyEnum a = (MyEnum)value; This is the example from that page: using System; [Flags] public enum PetType { None = 0, Dog = 1, Cat = 2, Rodent = 4, Bird = 8, Reptile = 16, Other = 32 }; public class Example { public static void Main() { … Read more
The default for an enum (in fact, any value type) is 0 — even if that is not a valid value for that enum. It cannot be changed.
It’s pretty easy, just use String or Int raw values which are implicitly assigned. enum PostType: Int, Codable { case image, blob } image is encoded to 0 and blob to 1 Or enum PostType: String, Codable { case image, blob } image is encoded to “image” and blob to “blob” This is a simple … Read more
The “correct” way is to define bit operators for the enum, as: enum AnimalFlags { HasClaws = 1, CanFly = 2, EatsFish = 4, Endangered = 8 }; inline AnimalFlags operator|(AnimalFlags a, AnimalFlags b) { return static_cast<AnimalFlags>(static_cast<int>(a) | static_cast<int>(b)); } Etc. rest of the bit operators. Modify as needed if the enum range exceeds int … Read more
Use the Apache commons lang3 lib instead EnumUtils.isValidEnum(MyEnum.class, myValue)