Redux Toolkit setup in React Native - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the function needed to create a Redux store.

React Native

import { [1] } from '@reduxjs/toolkit';

Drag options to blanks, or click blank then click option'

AconfigureStore

BcreateStore

CcreateReducer

DcombineReducers

Attempts:

3 left

💡 Hint

Common Mistakes

Using createStore which is from plain Redux, not Redux Toolkit.

Confusing combineReducers with store creation.

The configureStore function from Redux Toolkit is used to create the Redux store easily with good defaults.

2fill in blank

medium

Complete the code to create a slice with a name and initial state.

React Native

const counterSlice = createSlice({
  name: 'counter',
  initialState: [1],
  reducers: {}
});

Drag options to blanks, or click blank then click option'

A{ value: 0 }

B[]

Cnull

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number directly instead of an object.

Using null or an empty array which are not suitable here.

The initial state is usually an object with properties. Here, { value: 0 } sets the starting count.

3fill in blank

hard

Fix the error in the reducer function to correctly update the state.

React Native

reducers: {
  increment: (state) => {
    state.value [1] 1;
  }
}

Drag options to blanks, or click blank then click option'

A=

B+=

C==

D++

Attempts:

3 left

💡 Hint

Common Mistakes

Using assignment = which replaces the value.

Using comparison == which does not change the value.

Using ++ which is not valid syntax here.

To increase the value by 1, use the += operator. It adds 1 to the current state value.

4fill in blank

hard

Fill both blanks to export the reducer and actions from the slice.

React Native

export const { [1] } = counterSlice.actions;
export default counterSlice.[2];

Drag options to blanks, or click blank then click option'

Aincrement

Breducer

Creducers

Dactions

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to export 'actions' directly instead of specific action names.

Using 'reducers' instead of 'reducer' for the default export.

We export the increment action from counterSlice.actions and the default export is the reducer from the slice.

5fill in blank

hard

Fill all three blanks to configure the Redux store with the counter reducer.

React Native

const store = configureStore({
  reducer: {
    [1]: [2]
  },
  middleware: (getDefaultMiddleware) => getDefaultMiddleware().[3]()
});

Drag options to blanks, or click blank then click option'

Acounter

BcounterReducer

Cconcat

Dprepend

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'concat()' instead of 'prepend()' for middleware order.

Mixing reducer names or keys incorrectly.

The store reducer key is counter, the reducer function is counterReducer, and prepend() adds middleware at the start.

Practice

1. What is the main purpose of configureStore in Redux Toolkit?

easy

A. To create the Redux store with reducers and middleware setup automatically

B. To dispatch actions to update the store

C. To connect React components to the Redux store

D. To define action creators manually

Solution

1. Step 1: Understand configureStore role

   configureStore is a Redux Toolkit function that simplifies creating the Redux store by automatically combining reducers and adding middleware.

2. Step 2: Differentiate from other Redux tasks

   Dispatching actions and connecting components are done elsewhere, not by configureStore.

3. Final Answer:

   To create the Redux store with reducers and middleware setup automatically -> Option A

4. Quick Check:

   configureStore creates store [OK]

Hint: Remember: configureStore builds the store, not dispatch or connect [OK]

Common Mistakes:

• Confusing store creation with dispatching actions
• Thinking configureStore connects React components
• Assuming manual action creators are needed here

2. Which of the following is the correct syntax to create a Redux store using Redux Toolkit?

easy

A. const store = createStore(rootReducer);

B. const store = configureStore(rootReducer);

C. const store = configureStore({ reducer: rootReducer });

D. const store = new Store(rootReducer);

Solution

1. Step 1: Recall Redux Toolkit store creation syntax

   Redux Toolkit uses configureStore with an object argument containing the reducer key.

2. Step 2: Identify correct usage

   const store = configureStore({ reducer: rootReducer }); correctly passes an object with reducer: rootReducer. Options A and C use old or invalid syntax. const store = configureStore(rootReducer); passes reducer directly without an object, which is incorrect.

3. Final Answer:

   const store = configureStore({ reducer: rootReducer }); -> Option C

4. Quick Check:

   configureStore expects an object with reducer [OK]

Hint: Use configureStore({ reducer: ... }) syntax exactly [OK]

Common Mistakes:

• Passing reducer directly instead of inside an object
• Using createStore instead of configureStore
• Trying to instantiate Store with new keyword

3. Given this Redux Toolkit slice setup, what will be the initial state of the store?

import { configureStore, createSlice } from '@reduxjs/toolkit';

const counterSlice = createSlice({
  name: 'counter',
  initialState: { value: 10 },
  reducers: {
    increment: state => { state.value += 1; }
  }
});

const store = configureStore({ reducer: { counter: counterSlice.reducer } });

console.log(store.getState());

medium

A. { counter: { value: 0 } }

B. {}

C. { value: 10 }

D. { counter: { value: 10 } }

Solution

1. Step 1: Identify initialState in slice

   The slice defines initialState: { value: 10 } for the counter.

2. Step 2: Understand store state shape

   The store combines reducers under the key counter, so the state shape is { counter: { value: 10 } }.

3. Final Answer:

   { counter: { value: 10 } } -> Option D

4. Quick Check:

   Initial state matches slice's initialState under reducer key [OK]

Hint: Initial state is inside reducer key in store state [OK]

Common Mistakes:

• Ignoring reducer key nesting in state
• Assuming initial value is 0 by default
• Confusing slice state with root state shape

4. Identify the error in this Redux Toolkit store setup code:

import { configureStore } from '@reduxjs/toolkit';

const store = configureStore(reducer: rootReducer);

export default store;

medium

A. Missing curly braces around the reducer argument object

B. Using configureStore instead of createStore

C. rootReducer should be a string, not a variable

D. Export statement is incorrect

Solution

1. Step 1: Check configureStore argument syntax

   configureStore expects an object argument, so the reducer must be inside curly braces: { reducer: rootReducer }.

2. Step 2: Verify other parts

   Using configureStore is correct. rootReducer is a variable, which is valid. Export statement is fine.

3. Final Answer:

   Missing curly braces around the reducer argument object -> Option A

4. Quick Check:

   configureStore({ reducer: ... }) needs braces [OK]

Hint: Always pass an object with reducer key to configureStore [OK]

Common Mistakes:

• Passing reducer directly without braces
• Confusing configureStore with createStore
• Thinking export default is wrong here

5. You want to connect your React Native app to Redux using Redux Toolkit. Which is the correct way to wrap your app component to provide the store? A) <Provider store={store}><App /></Provider> B) <StoreProvider store={store}><App /></StoreProvider> C) <ReduxProvider store={store}><App /></ReduxProvider> D) <App store={store} />

hard

A.

B.

C.

D.

Solution

1. Step 1: Identify the correct provider component

   Redux Toolkit uses the Provider component from react-redux to supply the store to the app.

2. Step 2: Confirm correct usage

   The Provider wraps the root App component with the store prop. Other options use incorrect or nonexistent components.

3. Final Answer:

   <Provider store={store}><App /></Provider> -> Option B

4. Quick Check:

   Use Provider from react-redux to connect store [OK]

Hint: Wrap app in for Redux connection [OK]

Common Mistakes:

• Using wrong provider component names
• Passing store as a prop directly to App
• Forgetting to wrap the app at all