Utility Types

Partial

interface User {
  id: number;
  name: string;
  age: number;
}

let partialUser: Partial<User> = {
  name: "Alice",
};

Readonly

let readonlyUser: Readonly<User> = {
  id: 1,
  name: "Bob",
  age: 25,
};

// readonlyUser.age = 26; // Error: cannot reassign a readonly property

Pick

type UserName = Pick<User, "name">;

let userName: UserName = {
  name: "Charlie",
};

Omit

type UserWithoutAge = Omit<User, "age">;

let userWithoutAge: UserWithoutAge = {
  id: 2,
  name: "Dave",
};

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