Understanding TypeScript Generics

Generics start as a small syntax change—angle brackets around a type parameter—but they unlock reusable, type-safe abstractions.

function useFetch<TData>(url: string): Promise<TData> {
  // ...implementation
}

The TData placeholder lets you tell TypeScript what you expect back. Consumers get autocomplete, error reporting, and refactoring help for free.

Patterns to try

• Generic React components with discriminated unions.
• Utility types for state machines.
• API clients that infer response payloads.

Generics are not scary. Start by adding them to helper functions, then graduate to components and hooks.