JavaScript competitive tests
As you know, JavaScript is a programming language commonly used in web development. It was originally developed by Netscape as a means to add dynamic and interactive elements to websites. Like server-side scripting languages, such as PHP and ASP, JavaScript code can be inserted anywhere within the HTML of a webpage.
ReactJS basically is an open-source JavaScript library which is used for building user interfaces specifically for single-page applications. It’s used for handling view layer for web and mobile apps. React also allows us to create reusable UI components. React was first created by Jordan Walke, a software engineer working for Facebook.
Moreover, react is much faster as compared to the JavaScript frameworks. It makes use of the virtual DOM which minimizes the memory consumption and the DOM manipulation expenses.
Advantages of ReactJS
1. Simplicity: ReactJS is just simpler to grasp right away. The component-based approach, well-defined lifecycle, and use of just plain JavaScript make React very simple to learn, build a professional web (and mobile applications), and support it. React uses a special syntax called JSX which allows you to mix HTML with JavaScript. This is not a requirement; Developer can still write in plain JavaScript but JSX is much easier to use.
2. Easy to learn: Anyone with basic previous knowledge in programming can easily understand React while Angular and Ember are referred to as ‘Domain-specific Language’, implying that it is difficult to learn them. For React, you just need basic knowledge of CSS and HTML.
3. Naive Approach: React can be used to create mobile applications (React Native). And React is a diehard fan of reusability, meaning extensive code reusability is supported. So at the same time, we can make IOS, Android and Web application.
4. Data Binding: React uses one-way data binding and an application architecture called Flux controls the flow of data to components through one control point – the dispatcher. It's easier to debug self-contained components of large ReactJS apps.
5. Performance: React does not offer any concept of a built-in container for dependency. You can use Browserify, Require JS, ECMAScript 6 modules which we can use via Babel, ReactJS-di to inject dependencies automatically.
6. Testability: ReactJS applications are super easy to test. React views can be treated as functions of the state, so we can manipulate with the state we pass to the ReactJS view and take a look at the output and triggered actions, events, functions, etc.
Features of ReactJS
1. JSX: In React, instead of using regular JavaScript for templating, it uses JSX. JSX is simple JavaScript which allows HTML quoting and uses these HTML tag syntaxes to render subcomponents. HTML syntax is processed into JavaScript calls of React Framework. We can also write in pure old JavaScript.
2. React Native: React has native libraries which were announced by Facebook in 2015, which provides the react architecture to native applications like IOS, Android and UPD.
3. Single-Way data flow: In React, a set of immutable values are passed to the components renderer as properties in its HTML tags. Component cannot directly modify any properties but can pass a call back function with the help of which we can do modifications. This complete process is known as “properties flow down; actions flow up”.
The JavaScript tests that we covered in SkillPractical are: 1. JavaScript(Latest) 2. Angular 3. ReactJS 4. NodeJS
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SkillPractical has JavaScript learning path that helps the user to learn the Java from scratch. If user have any questions on JavaScript while attempting tests, he can post a question in SkillPractical community. They will get an answer from our expert consultants.



















