[TECH-QA] "TypeScript의 강력한 도구: 유틸리티 타입 활용법"

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

type PartialUser = Partial<User>;
// PartialUser = { name?: string; age?: number; }

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

type RequiredUser = Required<User>;
// RequiredUser = { name: string; age: number; }

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

type ReadonlyUser = Readonly<User>;
// ReadonlyUser = { readonly name: string; readonly age: number; }

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

type PickUser = Pick<User, 'name' | 'age'>;
// PickUser = { name: string; age: number; }

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

type OmitUser = Omit<User, 'email'>;
// OmitUser = { name: string; age: number; }

type Role = 'admin' | 'user' | 'guest';
type UserRecord = Record<Role, string>;
// UserRecord = { admin: string; user: string; guest: string; }

type MyUnion = 'a' | 'b' | 'c';
type Excluded = Exclude<MyUnion, 'a'>;
// Excluded = 'b' | 'c'

type MyUnion = 'a' | 'b' | 'c';
type Extracted = Extract<MyUnion, 'a' | 'b'>;
// Extracted = 'a' | 'b'

type Nullable = string | null | undefined;
type NonNullableType = NonNullable<Nullable>;
// NonNullableType = string

function getUser() {
  return { name: 'Alice', age: 30 };
}

type UserReturn = ReturnType<typeof getUser>;
// UserReturn = { name: string; age: number; }

function add(a: number, b: string): string {
  return `${a}${b}`;
}

type AddParams = Parameters<typeof add>;
// AddParams = [number, string]

type PromiseType = Promise<string>;
type ResolvedType = Awaited<PromiseType>;
// ResolvedType = string

type Greeting = 'hello world';
type UpperGreeting = Uppercase<Greeting>;
// UpperGreeting = 'HELLO WORLD'
type CapitalizedGreeting = Capitalize<Greeting>;
// CapitalizedGreeting = 'Hello world'