Reusable Type Modeling with Generics
Use generics to model real-world patterns like typed collections, enriched objects, and reusable response structures without losing type safety.
Learning generics isn’t just about angle brackets and type placeholders. It’s about building systems—clean, scalable type systems that reflect our app’s logic.
TypeScript is especially effective when we start designing reusable type models: tools we can apply repeatedly across features, APIs, and domains. This is what the current lesson covers.
Let’s first get familiar with the generic types that come built into TypeScript.
Introducing built-in generic types
We’ve used arrays, promises, and objects in JavaScript for years. To bring precision and predictability to these patterns, TypeScript provides generic types for common structures such as arrays, promises, and object maps or records. These generic forms let us describe the exact kind of values we’re working with—not just that we have a collection or an asynchronous action, but precisely what’s inside it.
Let’s look at a few of the most common ones in action.