Mastering TypeScript Generics

Generics are one of TypeScript's most powerful features, yet they can be intimidating at first. Let me share what I've learned.

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At its core, a generic is a way to create reusable components that work with multiple types:

function identity(arg: T): T {
  return arg;
}
const result = identity("hello"); // type is string
const number = identity(42); // type is number

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Here's a practical example for API responses:

interface ApiResponse {
  data: T;
  error: string | null;
  loading: boolean;
}
async function fetchData(url: string): Promise> {
  // implementation
}

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You can constrain generics to specific types:

function getProperty(obj: T, key: K): T[K] {
  return obj[key];
}

Understanding generics has significantly improved my code quality and developer experience.