Enforcing the type of the indexed members of a Typescript object?

Question

I would like to store a mapping of string -> string in a Typescript object, and enforce that all of the keys map to strings. For example:

var stuff = {};
st         


        

Answer 1

Define interface

interface Settings {
  lang: 'en' | 'da';
  welcome: boolean;
}

Enforce key to be a specific key of Settings interface

private setSettings(key: keyof Settings, value: any) {
   // Update settings key
}