React

Что такое React?

React — это декларативная, эффективная и гибкая JavaScript библиотека для создания пользовательских интерфейсов. Она позволяет вам собирать сложный UI из маленьких изолированных кусочков кода, называемых «компонентами».

12. Why is switch keyword used in React Router v4?

A: <div> is used to encapsulate multiple routes inside the Router. The switch keyword, however, is used when you want to display only a single route to be rendered amongst the several defined routes. The <switch> tag matches the typed URL with the defined routes in sequential order. When the first match is found, it renders the specified route bypassing all the other routes.

20. What’s the difference between an Element and a Component in React?

A: React element is an object representation of some UI. Basically, it describes what you want to see on the screen. A React component, on the other hand, is a function or a class that optionally accepts input and returns a React element. This is also one of the common interview questions on ReactJS.

2. How is React different from Angular and VUE?

A: The core difference between React and Vue is that React lacks any form of “abstraction”. It’s very much just straight JavaScript. This brings some of the drawbacks of of JS.

If you’re a JS expert, React will give you more power. But if you are lacking the expertise, Vue will smooth some of the rough patches for you. It’s also worth noting that Vue doesn’t work with Arrow functions in the same way React does.

VUE.js was launched in 2014 and since then, it has been the most rapidly growing js framework. It is particularly useful for building intuitive interfaces while also being extremely adaptable. VUE is a web application framework that helps in making advanced single page applications.

Angular is a typescript based JavaScript application framework developed by Google, not a collection of libraries and it relies more on HTML than on JS. Despite the slowdown in recent years it’s actually used very widely for government and enterprise projects, which depend on a stable, well-established, and consistent ecosystem.

It is also known as Super-heroic JavaScript MVW Framework. Its initial purpose was to encounter the challenges of creating single page apps. AngularJS is the oldest version of the Angular framework.

In the end, they all have something to offer and being tribal about it is pointless and self-destructive.

23. What is the use of the arrow function in React?

A: The arrow function is something you should be familiar when preparing for React interview questions because this function is very important for React operations. It allows you to predict the behavior of bugs when passed as callbacks hence it prevents bugs caused by this altogether.