Redux & Redux Toolkit
/Beginner
What is RTK Query?
Definition
A powerful data fetching and caching tool built directly into Redux Toolkit. It is designed to simplify common cases for loading data in a web application.
Explain Like I'm New
Writing Redux Thunks for API calls is exhausting. You have to write 'loading', 'success', and 'error' logic every single time. RTK Query says: 'Just give me the URL. I will fetch the data, cache it, generate the loading spinners, and even write the React Hooks for you automatically.'
Real World Example
You define a `/users` endpoint. RTK Query automatically generates a React hook called `useGetUsersQuery()`. You drop that hook into your component, and it magically returns `{ data, isLoading, error }`.
Common Use Cases
- •Replacing Axios + Redux Thunk
- •Caching server data
- •Preventing duplicate API calls
Interactive Example
// ❌ OLD WAY: 50 lines of Thunks, Reducers, and useEffects. // ✅ NEW WAY (RTK Query in a Component): import { useGetPokemonByNameQuery } from './pokemonApi' export const PokemonView = ({ name }) => { // That's it. One line of code handles the fetch, the cache, and the loading state! const { data, error, isLoading } = useGetPokemonByNameQuery(name) if (isLoading) return <div>Loading...</div> if (error) return <div>Error!</div> return <div>{data.sprites.front_default}</div> }
Interview Questions
basic
- Do you need to install a separate package to use RTK Query?
intermediate
- How does RTK Query prevent duplicate requests if two components ask for the same data at the same time?