What are Pick and Omit utility types? | TypeScript Interview Questions

What You'll Learn

Pick<T, K> utility
Omit<T, K> utility
Use cases

Pick<T, K>

Creates a type with only the specified properties.

code.tsTypeScript

interface User {
  id: string;
  name: string;
  email: string;
  password: string;
  createdAt: Date;
}

// Only pick specific properties
type UserPreview = Pick<User, "id" | "name">;
// { id: string; name: string; }

type LoginCredentials = Pick<User, "email" | "password">;
// { email: string; password: string; }

Omit<T, K>

Creates a type excluding the specified properties.

code.tsTypeScript

// Exclude sensitive data
type PublicUser = Omit<User, "password">;
// { id: string; name: string; email: string; createdAt: Date; }

// Exclude multiple properties
type UserInput = Omit<User, "id" | "createdAt">;
// { name: string; email: string; password: string; }

Common Patterns

code.tsTypeScript

// API response without internal fields
type ApiUser = Omit<User, "password" | "createdAt">;

// Form data type
type UserForm = Pick<User, "name" | "email" | "password">;

// Combine with Partial for updates
type UserUpdate = Partial<Pick<User, "name" | "email">>;