ALTIMETRIK CORP INTERVIEW QUESTIONS

Here is the list React JS Interview Questions which are recently asked in Altimetrik Corp company. These questions are included for both Freshers and Experienced professionals. Our React JS Training has Answered all the below Questions.

1. State and Props to elaborate the concept with complete source code?

State is the local state of the component which cannot be accessed, modified outside of the component and equivalent to local variables in a function. Props, on the other hand, make components reusable by giving components the ability to receive data from their parent component in the form of props which are equivalent to function parameters.

2. What are stateless components in React.js?

Stateless components are components which don’t have any state at all, like a normal function with no render method. It has no lifecycle, so it is not possible to use lifecycle methods such as component Did Mount and other hooks.

3.What are the advantages and disadvantages of using React components?

Components are created (mounted on the DOM), grow by updating, and then die (unmounted on DOM). The advantages are it facilitates the overall process of writing components. It boosts productivity and facilitates further maintenance. It ensures faster rendering which guarantees stable code, SEO friendly.

The disadvantages are the high pace of development, JSX as a barrier. Poor Documentation is another con which is common for constantly updating technologies. React JS covers only the UI Layers of the app and nothing else.

4. What are the benefits of using React.js?

The benefits of using React JS:

Easy to learn and use.
Easy to create dynamic web applications.
Performance enhancement.
The support of handy tools.

Learn React JS Course in Chennai to become a React professional:

5. What is a router in React.js?

React Router is a routing library built on top of React, which is used to create routes in a React application. It enables multiple views in a single application by defining multiple routes in the React application. React Router allows the navigation among views of various components in a React Application.

6. What is Flux concept in ReactJS? Explain various flux elements including Action, Dispatcher, Store and View. Give a simple practical example of installing and using Flux in an application?

7. What is Flux in React.js?

Flux is an architecture that has a uni-directional data flow. It was developed by Facebook itself to use as architecture internally when working with React. Flux is made up of individual components namely – Action, Dispatcher, Stores and Controller Views.

8. What is high-level component lifecycle in React.js?

A higher-order component (HOC) is an advanced technique in React for reusing component logic. They are a pattern that emerges from React’s compositional nature. Concretely, a higher-order component is a function that takes a component and returns a new component.

9. What is JSX and how JSX can help applications in React.js?

JSX is a syntax extension to JavaScript and used to describe what the UI should look like. JSX may remind you of a template language, but it comes with the full power of JavaScript. JSX produces React elements.

10. What is low-level component lifecycle in React.js?

A journey to the React components internals. Components are created (mounted on the DOM), grow by updating, and then die (unmount on DOM). This is referred to as a component lifecycle. There are different lifecycle methods that React provides at different phases of a component’s life.

11. What is ReactJS-JSX? What are the advantages of using JSX? Explain basic code snippet of JSX with the help of a practical example?

React JSX is a React extension which allows writing JavaScript code that looks like HTML. In other words, JSX is an HTML-like syntax used by React that extends ECMA Script so that HTML-like syntax can co-exist with JavaScript/React code.

ADVANTAGES OF JSX

JSX helps us in keeping our code simpler and elegant when writing large pieces of code.
According to the React docs, most people find it helpful as a visual aid when working with UI inside the JavaScript code.
JSX also allows React to show more useful error and warning messages.

EXAMPLE:

JSX makes it easier to write React applications, JSX allows us to write HTML directly within the JavaScript code.

const myelement =<xmp><h1>I Love JSX!</h1>; ReactDOM.render(myelement, document.getElementById(root));

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ALTIMETRIK CORP INTERVIEW QUESTIONS