Partial<T> / Required<T>
class
Partial makes all properties optional; Required makes all properties required. Both create new types.
Syntax
Partial<Type> Required<Type>
Example
javascript
interface User {
id: number;
name: string;
email: string;
bio: string;
}
// All fields optional (for PATCH updates)
type UserUpdate = Partial<User>;
const patch: UserUpdate = { name: 'Alice' }; // valid
// All fields required
type FullUser = Required<User>;