Interface class with nested classes in Typescript

Question

I am trying to write up an interface class which also contains other classes but i am getting an error when i do so but not sure what is wrong:

Interface:

export interface Languages{
   static English = class{
        id: number,
        section:number,
        name: string
   },
   static Chinese = class{
        id: number,
        section: number,
        name: string
   }
}

Both static and English are showing errors stating: [ts] Property or signature expected. [ts] Cannot find name 'English'.

There's no static in an interface. An interface describes how the instance looks like. If you want to describe static members/methods you need to create a different interface to represent that, like you have with Array and ArrayConstructor for example — Nitzan Tomer
– Nitzan Tomer, Commented May 8, 2017 at 20:46

Igor · Accepted Answer · 2017-05-08 20:48:27Z

1

Interfaces is a contract, not an implementation. Your English and Chinese members are instances which is exactly what an interface cannot support. They are also static, which is also incorrect on an interface. You could refactor it like this:

export interface Languages{
   English: Language;
   Chinese: Language;
}

export interface Language {
    id: number;
    section:number;
    name: string;
}

A better design would be to use a dictionary or a list with a lookup especially if this is a non-fixed size list where languages may be added later. Something like this for example:

export interface Languages{
   getLanguageByCode(isoCode:string): Language;
   getLanguageById(id: number): Language;
   allLanguages: Language[];
}

edited May 8, 2017 at 20:48

answered May 8, 2017 at 20:43

Igor

62.5k10 gold badges111 silver badges181 bronze badges

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

Collectives™ on Stack Overflow

Interface class with nested classes in Typescript

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