What is Reactjs

React is a JavaScript library for building user interfaces. It was developed by Facebook and is often used for building single-page applications and mobile applications using React Native.

React allows you to build reusable UI components, and makes it easy to manage the state of your application. It can be used with a variety of other technologies and is often used with libraries like Redux to build complex applications.

Redux is a JavaScript library for managing application state. It was developed specifically for use with React, but can also be used with other view libraries.

One of the key features of Redux is that it allows you to manage the state of your application in a single, immutable store. This makes it easier to reason about the state of your application and makes it easier to debug problems.

Redux uses a simple pattern called a "reducer" to specify how the state of the application should be modified in response to actions. Reducers are pure functions that take in the current state and an action and return the next state. This makes it easy to understand how the state of the application is being modified and makes it easy to test the logic of your reducers.

Overall, Redux is a powerful tool for managing the state of your application and is often used in combination with React to build large, complex applications.

React uses a virtual DOM (a lightweight in-memory representation of the actual DOM) to optimize updates to the actual DOM, making it faster than other options that manipulate the DOM directly.

A virtual DOM (VDOM) is a lightweight in-memory representation of a DOM tree. It is a way to optimize updates to the actual DOM, which can be slow and expensive, especially in large applications.

When a component's state changes, the virtual DOM creates a new virtual tree to represent the updated UI. It then compares the new virtual tree to the previous one and calculates the minimum number of changes that need to be made to the actual DOM in order to bring it in line with the virtual tree. This process is known as "reconciliation".

By minimizing the number of changes that need to be made to the actual DOM, the virtual DOM can significantly improve the performance of a UI, especially in large and complex applications.

React, a popular JavaScript library for building user interfaces uses a virtual DOM to optimize updates to the actual DOM. Other libraries and frameworks also use virtual DOMs to improve performance.

Why learn Reactjs

There are several reasons why you might want to learn React:

1. Popularity: React is one of the most popular JavaScript libraries, and is widely used by companies such as Facebook, Instagram, Netflix, and Airbnb.

2. Reusable components: React allows you to create reusable components, which can make it easier to build and maintain large applications.

3. Performance: React uses a virtual DOM (Document Object Model) to optimize updates and improve application performance.

4. Learn once, write anywhere: React can be used to build web, mobile, and desktop applications.

5. Strong community: React has a large and active community, which means that there is a wealth of resources available, including documentation, tutorials, and third-party libraries.

Overall, learning React can be a good investment for those interested in front-end web development, as it is a popular and powerful tool that is widely used in the industry.

Reactjs uses

Some common use cases for React include:

1. Web applications: React is often used to build web applications, particularly those that are designed to be interactive and dynamic.

2. Mobile applications: React can be used to build native mobile applications for iOS and Android using the React Native framework.

3. Desktop applications: React can be used to build desktop applications using libraries such as Electron.

4. Progressive web applications (PWAs): React can be used to build PWAs, which are web applications that can be installed on a user's device and behave like native applications.

Overall, React is a versatile and widely used tool that is well-suited for building user interfaces for a variety of applications.

What JavaScript concepts are required when learning Reactjs

When learning React, it is important to have a strong foundation in JavaScript. In particular, you should be familiar with the following concepts:

1. Variables: In JavaScript, variables are used to store data.

2. Data types: JavaScript has several data types, including numbers, strings, and booleans.

3. Operators: Operators are used to perform operations on variables, such as assignment, arithmetic, and comparison.

4. Control structures: Control structures, such as loops and conditional statements, allow you to control the flow of your program.

5. Functions: Functions are blocks of code that can be called by name. They are often used to perform specific tasks or to abstract away complex code.

6. Objects: Objects are collections of key-value pairs that can represent real-world entities.

7. Arrays: Arrays are used to store collections of data.

8. Classes: In JavaScript, classes are used to create objects and define their behaviour.

It is also helpful to have a basic understanding of HTML and CSS, as these are used to structure and style the content that is displayed on a webpage.

Finally, you should be comfortable with the use of Git and the command line, as these tools are commonly used in the development of React applications.

Companies using Reactjs

React is a popular JavaScript library for building user interfaces, and is widely used by companies around the world. Some examples of well-known companies that use React include:

1. Facebook: React was developed by Facebook and is used extensively within the company for both internal and external projects.

2. Instagram: Instagram's web and mobile applications are built using React.

3. Netflix: Netflix uses React to build its user interface and improve the performance of its web application.

4. Airbnb: Airbnb uses React to build its web and mobile applications.

5. Dropbox: Dropbox uses React to build its web and mobile applications.

6. Asana: Asana, a project management tool, uses React to build its web application.

7. Tesla: Tesla uses React to build its web application.

8. Reddit: Reddit uses React to build its web application.

These are just a few examples of the many companies that use React. Overall, React is a popular choice for companies looking to build efficient and scalable user interfaces.

Reactjs popularity of use among developer

From statista website react ranks number 2 as the most used web framework in the year 2022.

From the above data is quite evident that reactjs popularity will continue to increase in the future as more companies strive to make their online presence impactful.

In this series, I will try to tackle everything in the reactjs ecosystem using reactjs roadmap from:

I will end today's episode here until next time keep on hacking!

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1. "The most important skill a programmer can have is the ability to learn new things." - John Carmack