typescript union either single or array code example

Example 1: typescript union types

type Cow = {
  name: string;
  moo: () => void;
};

type Dog = {
  name: string;
  bark: () => void;
};

type Cat = {
  name: string;
  meow: () => void;
};

// union type
type Animals = Cow | Dog | Cat;

Example 2: use type as value typescript

Typescript interfaces aren''t being compiled into the js output, and you can not use them at runtime