Advanced TypeScript: Generic Types & Utility Types

Why Generics Matter

Generics allow you to create reusable components that work with a variety of types while retaining full type safety.

interface ApiResponse<T> {
  data: T;
  status: number;
  message: string;
}

function handleResponse<T>(response: ApiResponse<T>) {
  if (response.status === 200) {
    return response.data;
  }
  throw new Error(response.message);
}

Essential Utility Types

• Partial<T>: Makes all properties optional.
• Pick<T, K>: Constructs a type by picking keys K from T.
• Omit<T, K>: Constructs a type by picking all keys from T and then removing K.
• Record<K, T>: Constructs an object type with property keys K and values T.

Type Inference vs Explicit Types

Learn when to let TypeScript infer types and when to be explicit to document your intent and catch errors early.