enums - w3toppers.com

Java enum valueOf() with multiple values?

This is probably similar to what you’re trying to achieve. public enum Language{ English(“english”, “eng”, “en”, “en_GB”, “en_US”), German(“german”, “de”, “ge”), Croatian(“croatian”, “hr”, “cro”), Russian(“russian”); private final List<String> values; Language(String …values) { this.values = Arrays.asList(values); } public List<String> getValues() { return values; } } Remember enums are a class like the others; English(“english”, “eng”, “en”, … Read more

How do I conditionally check if an enum is one variant or another?

First have a look at the free, official Rust book The Rust Programming Language, specifically the chapter on enums. match fn initialize(datastore: DatabaseType) { match datastore { DatabaseType::Memory => { // … } DatabaseType::RocksDB => { // … } } } if let fn initialize(datastore: DatabaseType) { if let DatabaseType::Memory = datastore { // … … Read more

How to define properties for Enum items

Short Answer You need a constructor, a field and a getter. Constructors Enum types can have constructors, provided that their access level is either private or default (package-private). You can not directly call these constructors, except in the enum declaration itself. Similar to classes, when you define an enum constant without parameters, you actually call … Read more

Do C++ enums Start at 0?

Per that standard [dcl.enum] The enumeration type declared with an enum-key of only enum is an unscoped enumeration, and its enumerators are unscoped enumerators. The enum-keys enum class and enum struct are semantically equivalent; an enumeration type declared with one of these is a scoped enumeration, and its enumerators are scoped enumerators. The optional identifier … Read more

namespaces for enum types – best practices

Original C++03 answer: The benefit from a namespace (over a class) is that you can use using declarations when you want. The problem with using a namespace is that namespaces can be expanded elsewhere in the code. In a large project, you would not be guaranteed that two distinct enums don’t both think they are … Read more

How to get an enum which is created in attrs.xml in code

There does not seem to be an automated way to get a Java enum from an attribute enum – in Java you can get the numeric value you specified – the string is for use in XML files (as you show). You could do this in your view constructor: TypedArray a = context.getTheme().obtainStyledAttributes( attrs, R.styleable.IconView, … Read more

How to use enum as index key type in typescript?

|undefined does not make a property optional, just means it can be undefined, there is a proposal to make |undefined members optional but currently it’s not implemented. You need to use ? after ] to make all properties optional { [key in DialogType]?: Dialog } You can use the dialog enum values as keys, but … Read more

Pass enums in angular2 view templates

Create an Enum: enum ACTIVE_OPTIONS { HOME = 0, USERS = 1, PLAYERS = 2 } Create a component, be sure your enum list will have the typeof: export class AppComponent { ACTIVE_OPTIONS = ACTIVE_OPTIONS; active: ACTIVE_OPTIONS; } Create a template: <li [ngClass]=”{ ‘active’: active === ACTIVE_OPTIONS.HOME }”> <a routerLink=”/in”> <i class=”fa fa-fw fa-dashboard”></i> Home … Read more

How to add extension methods to Enums

According to this site: Extension methods provide a way to write methods for existing classes in a way other people on your team might actually discover and use. Given that enums are classes like any other it shouldn’t be too surprising that you can extend them, like: enum Duration { Day, Week, Month }; static … Read more

How to get enum value by string or int

No, you don’t want a generic method. This is much easier: MyEnum myEnum = (MyEnum)myInt; MyEnum myEnum = (MyEnum)Enum.Parse(typeof(MyEnum), myString); I think it will also be faster.