What are some use cases for mapped types in TypeScript?

What are some use cases for mapped types in TypeScript?

Mapped types in TypeScript allow you to create new types by transforming properties of existing types. They are useful for creating variations of types without repeating code.

Can you give me an example of a mapped type?

Sure! For instance, you can create a mapped type that makes all properties of an existing type optional. Here's an example:

type User = { id: number; name: string; };

type PartialUser = { [K in keyof User]?: User[K]; };

What about use cases in real-world applications?

In real-world applications, mapped types can be used for creating forms where all fields are optional, or for generating types that represent API responses based on existing data models.

Are there any limitations to using mapped types?

Yes, one limitation is that mapped types can only transform properties of existing types, so they can't create new properties that don't exist in the original type.