Solution

The solution to the TypeScript exercise is as follows:

type Pet = {  name: string;  kind: 'cat' | 'dog' | 'fish';  age: number;  favouriteFoods: string[];  speak?: () => void;  owner: {    name: string;    age: number;  };};
const pets: Pet[] = [  {    name: 'Fluffy',    kind: 'cat',    age: 10,    favouriteFoods: ['fish', 'chicken'],    speak: () => console.log('meow'),    owner: {      name: 'Sarah',      age: 18,    },  },  {    name: 'Teddy',    kind: 'dog',    age: 2,    favouriteFoods: ['anything off your table'],    speak: () => console.log('woof'),    owner: {      name: 'Mary',      age: 24,    },  },  {    name: 'Bubbles',    kind: 'fish',    age: 1,    favouriteFoods: ['algae'],    owner: {      name: 'Steve',      age: 30,    },  },];