How to replace types in typescript?

Question

say I have

type Person = {
  name: string
  hobbies: Array<string>
}

and then this: const people: Array<Person> = [{name: "rich", age: 28}]

how do I add age AND replace hobbies with say a different type ( Array<number> ) to keep it simple

I know I can use omit to get rid of a property or intersections to add a property but I'm struggling to work it out

Obviously this is wrong but I want something like that

type Hobbies = Array<number>
type NewPerson = Omit<Person, "hobbies"> & Hobbies & Age

const people: Array<NewPerson> = [{name: "rich", age: 28, hobbies: [1,2,3]}]

Answer 1

You neet to intersect with object types that have the extra properties you want to add

type Hobbies = { numbers: Array<number>}
type NewPerson = Omit<Person, "hobbies"> & Hobbies  & { age: number }

const people: Array<NewPerson> = [{name: "rich", age: 28, numbers: [1,2,3]}]

Playground Link

Answer 2

You're right you'd use Omit and an intersection. To remove hobbies and add age you'd do Omit and intersect with an object type defining age and the new version of hobbies :

type Person = {
    name: string;
    hobbies: Array<string>;
};

type NewPerson = Omit<Person, "hobbies"> & { age: number, hobbies: number[] };

const people: Array<NewPerson> = [{ name: "rich", age: 28, hobbies: [1,2,3] }];

Playground link

Answer 3

Maybe the example below helps.

type NewPerson = Omit<Person, "hobbies"> & { hobbies: Array<number>, age: number }

const people: Array<NewPerson> = [{name: "rich", age: 28, hobbies: [1, 2, 3]}]

Use the Omit type to remove the hobbies property from the Person type and then add in the new hobbies and age properties.