REACT JS INTERVIEW QUESTIONS

ReactJs, also known as React, is a Facebook-developed open-source JavaScript library for front-end development. It’s used in Facebook, WhatsApp, and Instagram, among other things. It was originally maintained by Facebook, but it was later made open-source, and it now has a thriving developer community. React allows you to create reusable user interface components.

•React improves efficiency, to name a few.
•React ensures stable code 
•React makes the process of writing components easier React improves SEO performance

ReactJs is an incomplete library for creating user interface components; it is fundamentally different from a large number of other JavaScript structures. AngularJS, for example, constructs an app solely by expanding HTML markup and infusing different development such as controller at runtime.

The lifecycles of ReactJs are:

  • Destruction
  • Initialization
  • Property Updates

In today’s rapidly changing world, it is one of the most in-demand libraries for front-end expansion. It is defined as an unsurprising state container that is primarily intended for JavaScript apps but can also be used to organise an application’s entire state. Redux is a very small programme with no dependencies. It creates applications that are simple to set up and test in a variety of environments. Redux is a lightweight framework with no dependencies.

Redux Thunk functions as middleware, allowing users to mark action creators that return functions instead of actions. This can also be used as a holdup function to wait for an effort to be dispatched if a certain condition is met. The inside function takes two store methods as parameters: gestate () and dispatch ().

Flux is an important image that helps to maintain the unidirectional data stream. Its purpose is to control only fragments of construed data in order to create a border with that data without causing problems. The Flux pattern is uninteresting; it isn’t specific to react applications, and it isn’t required to collect a React application. Flux is a simple concept, but you must demonstrate a thoughtful understanding of how to apply it.

https://github.com/facebook/react

Yes, there are some challenges associated with this platform. The largest disadvantage of ReactJs is the size of its library. It has a lot of facets and causes a lot of confusion among developers. In addition, JSX and inline templating are disliked by many developers.

State is a concept in React that describes how a component renders and behaves. States are data sources that allow you to create dynamic and interactive elements. This is how you get to them. state(). This method is used to change a value in the state object. The setState() method is used to change the state of the system.

The following are some of React’s limitations:
•It has a large library that takes time to learn. 
•Coding becomes complicated because it uses inline tempting and JSX.
•React is a library, not a full-fledged framework, so it can be difficult to grasp for inexperienced programmers.

Only JavaScript objects can be read by browsers, but JSX is not a regular JavaScript object. To allow a browser to read JSX, we must first convert the JSX file into a Javascript object using JSX transformers such as Babel, and then pass it to the browser.

Refs. should be used for: • Triggering imperative animations • Integrating with third-party DOM libraries • Managing focus, selecting text, or playing media

React JS is a technology that can be credible for complex tasks. While performing any task through it, developers need not be worried about the bugs. It always ensures error-free outcomes and the best part is it offers scalable apps.

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