Learn to use React and JavaScript with an online course at W3schools. This comprehensive course includes all HTML and essential JavaScript elements, including Virtual DOM and components. In addition, it consists of a crash course in Reactjs, updated for 2021. You can even earn a certificate by completing the course.
JavaScript
This React JavaScript tutorial will teach you how to use props to pass arguments to React components. Props are HTML elements, much like attributes or parameters. However, the difference is that props are read-only. Therefore, you must use a valid value when passing these props.
React is an open-source JavaScript library for building user interfaces for web applications. Developed by Facebook, it is continuously evolving and adding new features. The tutorial starts by explaining the architecture of the library. It then covers setting up your project, creating components, and working with JSX. Finally, it concludes with a working example.
JSX
The React framework uses JavaScript XML (JSX) syntax to build web applications. JSX is like HTML, but with additional syntax, it is easier to write clean code. JSX also supports nested elements, which need to be wrapped inside a container element, such as a div.
The language uses curly braces to wrap expressions and objects. It also makes use of inline styles rather than styles in HTML. JSX also performs optimizations and is faster than regular JavaScript. React uses components that contain both markup and logic.
Virtual DOM
Virtual DOM is an abstraction of the DOM. Think of it as a lightweight representation of the real thing. For example, you can draw a room on paper, but it won’t change the actual space. The same thing happens with the DOM in a web application. The DOM comprises different nodes, each representing an element in the application.
The DOM is an object that a browser uses to display web content. A browser parses a page and extracts child elements from specific elements. These child elements are then removed from the DOM. The browser then recalculates CSS for all of the parent nodes. Finally, it traverses the tree to display what’s on the screen. This process is similar to updating a house’s blueprint.
Components
There are many different types of React components. For example, a part can be read-only or have a state and can be built in the constructor. To create a member, you first create a new component class and then add a constructor. When you’re done, you can render the component.
The constructor() function initiates a component and then sets the component’s state and props. These are stored in an object called a state. The constructor should honor inheritance from its parent component. If you have more than one component, use the super() statement to execute the parent component’s constructor function.
JavaScript tutorials
It is interested in learning how to create interactive web applications with the React JavaScript library. W3schools offers a complete course that teaches the fundamentals of this popular front-end development framework. Its interactive and structured tutorials are recommended by top institutions and companies worldwide.
The course will introduce you to the basic concepts and syntax of React. React is an open-source front-end JavaScript library that helps you build dynamic interactive web applications. Developed by Facebook, React is constantly evolving with new features. The tutorial will teach you how to set up a project, create components, and use JSX. Afterward, you’ll learn how to implement ReactJS in a working example.
Exam
W3schools is the leading developer learning website, offering certifications in React and Redux. These certifications are trusted by leading companies and institutions around the world. React is a JavaScript library for building user interfaces. If you’ve never used React before, W3schools offers free tutorials and practice exercises to help you become familiar with the library and its use.
The W3Schools course includes a quiz with 25 and 40 questions. Each question is scored, and you’ll get an overall score. In addition, you can review the questions to ensure you’re getting the correct answer.