Built-in helpers transform types quickly. Common ones: • Partial<T>, Required<T> • Readonly<T>, Mutable via -readonly in mapped types • Pick<T, K>, Omit<T, K> • Record<K, V> • ReturnType<T>, Parameters<T> • Awaited<T>
type DraftUser = Partial<User>;
type UserIdMap = Record<string, User>;type User = { id: string; name: string; email?: string };
type UserDraft = Partial<User>; // all optional
type UserRequired = Required<User>; // all required
type UserPreview = Pick<User, "id" | "name">;
type UserSansEmail = Omit<User, "email">;
type UserMap = Record<string, User>;
function makeUser(): User { return { id: "1", name: "Ada" }; }
type CreatedUser = ReturnType<typeof makeUser>;Understanding Utility Types is fundamental to mastering TypeScript. Practice with the examples above and experiment with variations to solidify your knowledge.