Author: saqibkhan

We can implement routing in our React application using this method:

Considering we have the components App, About, and Contact in our application:

Hope you have no doubts about this ReactJS interview questions article, in case of any difficulty, please leave your problems in the section below.

SN	React Routing	Conventional routing
1.	Single HTML page	Each view is a new HTML file
2.	The user navigates multiple views in the same file	The user navigates multiple files for each view
3.	The page does not refresh since it is a single file	The page refreshes every time user navigates
4.	Improved performance	Slower performance

• It maintains consistent structure and behavior and is used to develop single-page web applications. 
• Enables multiple views in a single application by defining multiple routes in the React application.

React Router is a routing library built on top of React, which is used to create routes in a React application. This is one of the most frequently asked react interview questions.

SN	Redux	Flux
1.	Redux is an open-source JavaScript library used to manage application State	Flux is an architecture and not a framework or library
2.	Store’s state is immutable	Store’s state is mutable
3.	Can only have a single-store	Can have multiple stores
4.	Uses the concept of reducer	Uses the concept of the dispatcher

• Flux is the application architecture that Facebook uses for building web applications. It is a method of handling complex data inside a client-side application and manages how data flows in a React application.

• There is a single source of data (the store) and triggering certain actions is the only way way to update them.The actions call the dispatcher, and then the store is triggered and updated with their own data accordingly.

• When a dispatch has been triggered, and the store updates, it will emit a change event that the views can rerender accordingly.

• Store: Holds the state of the application.
• Action: The source information for the store.
• Reducer: Specifies how the application’s state changes in response to actions sent to the store.

Redux is an open-source, JavaScript library used to manage the application state. React uses Redux to build the user interface. It is a predictable state container for JavaScript applications and is used for the entire application’s state management.

• getInitialState(): This is executed before the creation of the component.
• componentDidMount(): Is executed when the component gets rendered and placed on the DOM.
• shouldComponentUpdate(): Is invoked when a component determines changes to the DOM and returns a “true” or “false” value based on certain conditions.
• componentDidUpdate(): Is invoked immediately after rendering takes place.
• componentWillUnmount(): Is invoked immediately before a component is destroyed and unmounted permanently.

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ReactJS Redux Interview Questions

Here are some ReactJS Interview Questions on the ReactJS Redux concept.

	Class Components	Functional Components
State	Can hold or manage state	Cannot hold or manage state
Simplicity	Complex as compared to the stateless component	Simple and easy to understand
Lifecycle methods	Can work with all lifecycle methods	Does not work with any lifecycle method
Reusability	Can be reused	Cannot be reused

• Class components example:

• Functional components example: