Understanding discriminated union and intersection types in TypeScript

Understanding union and intersection types in TypeScript involves exploring their mathematical origins in set theory and their practical applications in the language. Union types in TypeScript allow a value to be one of several types, akin to the OR operator, while intersection types combine multiple types into one, similar to the AND operator. These concepts help improve code flexibility and type safety, with union types enabling a function to accept multiple types, and intersection types ensuring that all properties of combined types are present. Discriminated unions, which include a common property to differentiate among types, aid in pattern matching and are particularly useful in error handling scenarios. The article provides examples of how these types are implemented in TypeScript, including addressing common errors such as accessing properties not present on all types within a union. Additionally, it discusses advanced topics like conditional intersections via union types, offering developers tools to enhance code robustness and maintainability.