Redux Basic Interview Questions : Most asked Interview Questions for Freshers

Redux Basic Interview Questions : For JavaScript apps, Redux is a reliable state management library. It facilitates easier understanding, debugging, and testing by offering a centralized store to manage the state of the application. The store, reducers, and actions are some of Redux’s core ideas. Simple JavaScript objects called actions are used to represent state changes. Reducers are simple functions that return a new state after receiving an action and the current state. The store, which stores the current state and initiates activities, is the only source of truth for the state of the application.

A software engineer that focuses on utilizing Redux to manage the state of JavaScript applications is known as a Redux developer. They are proficient in using Redux to create scalable and maintainable systems because they have a solid grasp of its principles and best practices. Redux developers can utilize Redux with different JavaScript frameworks or libraries, but they often work with React. They are in charge of creating reducers, sending actions, and planning the state structure of the application

here are some Redux Basic Interview Questions :  Most asked Interview Questions for Freshers

1.What is Flux?

Programming’s Flux paradigm offers a declarative approach to application state management. Flux depends on unidirectional data flow, in contrast to typical imperative programming, where state changes are explicitly declared. This eliminates complicated dependencies and facilitates reasoning about an application’s current state by allowing data to flow in a single path.

The state of the application is kept in a central store in Flux. Actions are sent to the store in the form of user interactions or system events. Subsequently, the store modifies its state according to the operation and the logic of the application. The view components then re-render themselves to reflect the modified state after receiving the updated state. The application state is kept consistent and predictable with the aid of this one-way data flow.

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2.What is Redux in React js?

React.js and other JavaScript apps use Redux, a predictable state container. It makes application state management more centralized and facilitates debugging and comprehension. Redux stores the whole state of an application in a single object called the store. Changes to the state are represented by actions, which are transmitted to the store. Then, using reducers—pure functions that accept an action and the current state as inputs and produce a new state—the store modifies its state.

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3.  What do you understand about Redux Toolkit?

Redux Toolkit is a set of applications and tools made to make using Redux in React.js projects easier. It has a number of characteristics that make code maintainability better and the development process more efficient. The create Slice function, one of the main components of Redux Toolkit, enables developers to construct application state slices and the associated actions and reducers in a clear and structured way.

Furthermore, Redux Toolkit comes with integrated support for popular Redux patterns like async thunks, which let Redux perform asynchronous operations. Additionally, it has tools for managing routine state management activities. One such tool is immer, which enables immutable state modifications without requiring the creation of new objects by hand. These features make writing Redux code easier, more effective, and clearer for developers.

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4.  What is the mental model of redux saga?

Redux Saga is a middleware module for Redux that makes handling side effects in your application more clear and understandable. It defines sagas—independent functions that can be used to handle asynchronous tasks like timers and API calls—using generators.

Redux Saga’s mental model asks you to see sagas as separate processes that operate in parallel with your primary application. Every tale can be stopped, resumed, or ended like a little, self-contained machine. Redux Saga determines whether any sagas are interested in taking on an action when it is dispatched. A saga can initiate a new task to manage the action if it is interested. Using Redux actions, this job can change the application state and carry out asynchronous tasks. Using sagas helps you manage side effects in a more predictable and orderly manner, which makes it easier to understand and maintain your Redux apps.

5.What are actions in Redux?

Redux actions are simple JavaScript objects that indicate modifications to the state of the application. They are the main means of inducing state updates and interacting with the Redux store. Actions usually include any additional information required to complete the state change, along with a type property that uniquely identifies the action.

An action is passed to the Redux store upon dispatch. Next, depending on the action type and payload, the store utilizes reducers to decide how to update the state. Reducers are simple functions that return a new state after receiving as inputs the action and the current state. You can start state modifications and update the components that rely on that state by dispatching actions.

6.Describe what a reducer is in Redux.

In Redux, reducers are pure functions that return a new state after receiving as inputs the action and the current state. They are in charge of updating the state of the application in accordance with the actions sent to the store. Reducers need to be pure functions, which means they need to always return the same result for the same input and not have any side effects.

Generally speaking, reducers are just basic functions that handle various action kinds with a switch statement. Every case in the switch statement denotes a certain kind of action and specifies how the action’s state should be modified. Because the same action will always result in the same state update, reducers let you make sure that the state of your Redux application is always predictable and consistent.

7.What is the purpose of middleware in Redux?

Middleware in Redux enables a third-party extension point between dispatching an action and the instant it reaches the reducer. It is frequently utilized for managing asynchronous operations, reporting crashes, and logging.

Complex state logic or side effects can be managed by implementing middleware such as redux-thunk or redux-saga. A strong applicant will describe how middleware expands Redux’s capability by enabling more intricate operations.

8.What is the role of the store in Redux?

The central repository for all application state is the Redux store. It contains a single, unchangeable object that symbolizes the application’s current state. The application’s behavior is easier to comprehend and rationalize because to this centralized state management.

The Redux store employs reducers to decide how to change the state when an action is dispatched. Reducers are simple functions that return a new state after receiving as inputs the action and the current state. Next, any components that rely on the updated state are immediately re-rendered by the store as it replaces the old state with the new one. This guarantees that the application’s current state is always reflected in the user interface.

9.Explain the concept of selectors in Redux.

Redux selectors are functions that choose out particular sections of the application’s state. They facilitate the use of the state in components and other areas of the program by extracting computed values from it. Selectors are essentially pure functions that accept the complete state of the program as input and output a single piece of data.

Selectors help you make your components more reusable and understandable by preventing you from passing down pointless state props to them. Moreover, selectors can be used to generate memoized values, which enhance performance by storing the outcomes of costly computations. Large or complicated applications where the state may be modified frequently will find this very helpful.

10.How would you implement real-time updates in a Redux application?

Redux with a real-time communication protocol, such as WebSockets, are usually used in conjunction to implement real-time updates in a Redux application. Here’s a basic strategy:

• To get updates in real time from the server, set up a WebSocket connection.
  Make a middleware to manage messages from WebSockets.
  Take action in response to the messages you have received.
• In light of this, update the Redux store.
• The store-connected React components will immediately re-render with the updated information.

11.What do you understand by Redux Thunk?

With Redux Thunk, a middleware library, you may use functions in Redux as actions. This lets you do asynchronous tasks in your Redux reducers, including handling timeouts and making API requests.

Redux Thunk intercepts a thunk function dispatch and uses the dispatch function as a parameter when calling the function. This enables you to carry out asynchronous tasks and schedule activities for a later date. A thunk could be used, for instance, to initiate an API call and, upon receiving the response, to initiate an action. This keeps your reducers tidy and concentrated on updating the state, and it also makes managing asynchronous logic within your Redux application easier.

12. Can Redux and RxJS work together?

Indeed, Redux and RxJS can function well together. Even though they have separate functions, they can work in tandem to manage the state of an application and handle asynchronous actions.

For JavaScript applications, Redux offers a centralized state management solution, and RxJS is a framework for reactive programming that lets you work with data streams. You may build a strong and adaptable application architecture by integrating Redux and RxJS. RxJS, for instance, can be used to generate observables that represent asynchronous data streams. Redux actions can then be sent out in response to the values that these observables output. This makes your code more readable and concise by enabling you to manage asynchronous tasks in a declarative and reactive manner.

13.Can We access a redux store outside a react component?

Yes, you can access a Redux store outside a React component. Although managing state in React apps is Redux’s main use case, there are times when you may need to access the store from other areas of your application.

One such situation is having to carry out asynchronous actions outside of React components, like server-side rendering or background tasks. In these situations, you can utilize the Redux store directly to import the current state or to dispatch actions. Nevertheless, accessing the store outside of components may have unintended consequences that make your application less reliable and more difficult to test.

14.What is Redux DevTools?

A well-liked open-source package, or extension (it may be used as both), Redux DevTools offers an application debugging environment. It offers live editing and time-travel debugging tools. After making changes to the reducer code, we can use devtools to check the state, action payload, and even reevaluate the staged action.

15.What is the Provider component in React-Redux?

In React-Redux, the Provider component is a higher-order component that allows all of its child components to access the Redux store. It encapsulates your React application’s top-level component and offers a mechanism to distribute the store to every component in the component tree.

A component uses context to access the store when it is rendered inside the Provider component. This means that components can access the store’s state and dispatch actions by using the connect higher-order component or the useSelector hook. You can manage state across your components and include Redux into your React application with ease by utilizing the Provider component.

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