Progression

TypeScript · Intermediate - build real things

• type vs interface: extends and intersectionPick the right construct to model and compose your object types without duplicating code.
• Literal types and discriminated unionsModel your application's states with unions the compiler checks on your behalf.
• Enums and const assertions: the modern alternativesUnderstand the limits of enums and derive your types from frozen constants with as const.
• Generics: simple generic functions and typesWrite reusable functions and types that keep full type precision on every call.
• Typing real-world code: DOM, fetch, JSONKeep reliable types at your application's boundaries, where the DOM, the network, and JSON escape the compiler.