Building Mapped Types and Utility Types

TypeScript types

In addition to limiting variables to a set of specific literal values and defining enums, TypeScript allows us to define types that are based on other types, much like super-powered generics. These are called mapped types. TypeScript also has many predefined mapped types that it calls utility types.

So, let’s say we have our existing type TicketData:

interface TicketData {
 

...