React JS Training in Bangalore

ReactJS

React is a JavaScript library predominantly used for the development of User Interfaces (UI) and web applications. React is also used to build single-page, mobile, and server-rendered applications. It is an open-source, component-based front-end library responsible for the application’s view layer. React was developed by Meta (then Facebook), accompanied by a community of individual developers and companies with its release being in 2013. React has grown in popularity since its inception owing to its efficiency, scalability, and the developer-friendly approach it offers for building modern web applications.

Prerequisites for learning React JS

Before learning React, it is beneficial to have the knowledge of the following tools and technologies.

• HTML
• CSS
• Javascript
• ES6+
• Node JS
• Package Manager
• Git and CLI (Command Line Interface)
• HTTP
• JSON

Features of React JS

JSX

JSX stands for Javascript XML. JSX enables developers to write HTML code in React. This feature makes it easier to create and manage the structure and appearance of user interfaces. This also makes React JS faster than standard Javascript since JSX performs optimization while compiling the source code to JavaScript.

JSX is like writing your use­r interface directly within your JavaScript code­. While this may seem unconve­ntional, it offers several vital be­nefits. For instance, JSX allows React to show more critical warning messages and can even optimize your code­ for faster execution when translated into regular JavaScript.

JSX also offers the advantage of simplifying template creation and user interface de­sign.

JSX, being a JavaScript e­xpression, also offers diverse applications within the code written. It can be utilized in if state­ments and loops, stored in variables, passe­d as arguments to functions, or even re­turned from functions. This versatility grants it immense­ potential for constructing dynamic and engaging user inte­rfaces.

Virtual DOM

DOM stands for Document Object Model.The DOM is a programming interface that represents both structure and content of a web page or web application. Usage of real DOM has some disadvantages such as performance issues, complexities, memory consumption. React JS solves this by using virtual DOM, which is actually a copy of the real DOM.

Here­’s how it works: Instead of directly instructing React to change­ the DOM, which can be slow, you provide Re­act with instructions on how you want your page to appear based on the­ current situation. Subsequently, Re­act utilizes the Virtual DOM to dete­rmine the most efficie­nt method for aligning the real DOM with your guide lines. This eliminates any conce­rns about manipulating intricate DOM details as React handle­s this process on your behalf.

The Virtual DOM can be­ likened to a blueprint that dictate­s how your web page should transform. Whene­ver there are­ changes in your application, React gene­rates a fresh blueprint known as the­ new Virtual DOM. Subsequently, it compare­s this updated plan with the previous one­ to identify the disparities.

Unidirectional Data Flow

React JS is designed in such a way that it follows unidirectional data flow. It means that data is transferred from top to bottom only i.e. parent component to child component.Child components cannot independently edit or modify the data they receive. Instead, they rely on data passed from parent components, which helps organize your data and makes your application more predictable. Data from parent components in React are often called “props”. Two-way data bindings are avoided to achieve an unadulterated data flow design through React. This approach offers several advantages:

State Management: By way of data flowing from parents, child components can better manage their part of the application state.

Action Control: By the user or UI, changes in an application are typically brought about through actions. Update the state, which is then passed on to the children.

Control: With React, you have more power to manage and update data via single-way data streams. Easier comprehension and upkeep arise from this, allowing for more efficient software development.

Component based Architecture

Components in React are like independent and reusable building blocks of your web application. They are similar to JavaScript functions but run in isolation and return HTML. Think of components as small, self-contained parts of your user interface. In React, components play an essential role and are the basic building blocks of your application. Every application you use React with is built with these features. This approach makes the process of creating a user interface much more manageable.

Imagine breaking down your user interface into smaller, individual chunks called components. Each piece can be designed and used independently. You can combine these objects in the parent object, creating your end-user interface. Together, the components make up the complete UI of your application.

Interestingly, each part of React has its own framework, methods, and APIs. This means they are highly reusable. You can use and customize the features as needed, making your development process more efficient and easier to maintain your code.

State

A state in a React component is a built-in attribute that is basically a container for storing property values specific to that component. It is a dynamic, scalable system for holding data or information associated with an object. The state may change over time, responding to user actions or system events. When the state changes, the component renders to reflect that change. Objects with such potential are known as stateful components.

The state is like the heart of a React component. It shows the behaviour of the component and displays it on screen. Stateful components are vital in making your UI dynamic and interactive. They allow you to maintain and update data in the component as needed.

In React, a state is represented as a React Component Class instance, which acts as an object with observable properties that control the component’s actions. Think of it as a container of information that can evolve or change during the component’s lifetime. So whenever something triggers a state change, it tells the user how the object behaves and what is expressed.

Hook

React introduced Hooks in version 16.8 that has changed the way functional components work. Previously, developers could only manage state and other React features with class components. But Hooks allows you to have the same functionality in different functional components, making applying programming principles in React easier.

Hooks enable functional components to implement state in React and manage side effects. They provide access to React’s status and lifecycle features without needing class-based syntax. Threads are explicitly designed to be used in objects and not in classes.

An important point to remember is that Hooks are backward-compatible, which means it does not cause breaking changes. They don’t even replace your existing knowledge of React concepts. Previously, if you wanted to add a state to a function component, you had to convert it to a class component. But now, you can add Hook to your existing project component, simplifying your development process.

Props

In React, we can pass data to a component using the concept of “props”, which is short for “properties”. Props are basically read-only objects that behave like HTML attributes. They are a way of transferring information from one object to another, like transferring meaning to a project. When using props, you define attributes in the component, which can then be accessed as ‘this.props’ in the component. These attributes allow you to define data in the component’s ‘render’ method dynamically.

It’s important to note that props are immutable, so you can’t change them in the component. Instead, they are a way to provide the object with data from its parent or external source. Essentially, React props act as a tool to pass information to components and are passed to components when you pass logic to a function. They are similar to function arguments in JavaScript and attributes in HTML.