In today’s tech-dominated world, almost every business has its own web application. People are highly dependent on these web applications to fulfil their daily needs and requirements- from ordering grocery to booking cabs and even making online payments everything is on the phone today.
But have you ever wondered about how all these robust applications are made? So there are various top programming languages and libraries into action. One such strong and reliable Javascript library commonly used in enhancing user experience is React JS. Today, in this tutorial we will understand what react JS is, by getting familiar with its features, advantages and various functions.
React JS – Key Takeaways
- Understanding what is react and why to use it.
- Getting insights into features of React JS.
- Understanding the core concepts in React JS.
- Learning React JS advantages and disadvantages.
What Is React JS?
React JS is a strong and reliable library of JavaScript that was built by Facebook in 2013. It is known for making user interfaces, especially for websites and apps. With React, you can build parts of a webpage that can change without reloading the whole page. This makes the experience faster and smoother for users. React is popular because it helps web developers to create dynamic and responsive web pages quickly and efficiently.
Why To Use React JS?
Being very new to the tech market, React has become the most popular choice for front-end development in very less time by surpassing other front end frameworks. Some of the reasons behind its wide popularity are written below for your reference:
- Easier to Build Dynamic Apps: React simplifies the creation of dynamic web applications. It requires less coding and offers more features.
- Better Performance: React uses something called Virtual DOM, which makes web applications faster. Instead of updating everything when something changes, Virtual DOM only updates the changed part which makes the process much quicker as compared to others.
- Reusable Components: React offers plenty of components that can be reused in different parts of your app, this basically saves a lot of time and effort during development.
- One-Way Data Flow: React follows a one-way data flow, which means that the data moves in a single direction only. This makes it easier to find and fix errors because you know exactly where the problem is happening.
- Easy to Learn: React is very easy to learn as compared to other front end frameworks. It mainly uses basic HTML and Basics of JavaScript, with a few extra features.
- Works for Both Web and Mobile Apps: React is not just for web applications. With React Native, which is mainly built on React, you can also create mobile apps. So, React can be used for both web and mobile development.
- Simple Debugging: Facebook has made a React Chrome extension specifically for debugging React apps. Using this tool makes it easier to find and fix issues in your React application.
These reasons explain why React is so popular and why many companies choose to use it. Now, let’s explore the features of React JS
Features Of React JS
Have you ever wondered why React is so popular among all the front-end frameworks? The main reason behind its popularity is the many new and exciting features it offers. Below, we’ve explained some key features of React JS that make it a standout choice in the market.
1. JSX
JSX basically stands for JavaScript XML. It is a JavaScript syntax extension mainly used with React to describe how the user interface should look. With JSX, you can write HTML-like code inside your JavaScript module. Instead of writing long and complex JavaScript code to create elements, you can use simple, familiar HTML tags to create a visually appealling User interface. Let us understand this better with the help of the example given below-
| Example Of JSX |
| Const name = ‘PWSkills’;
const greet = <h1>Hello, {name} </h1>; |
This code written above looks like HTML but is actually an example of HTML being embedded in JS code. When React sees this code, it automatically converts it into the proper JavaScript code that the browser understands.
2. Virtual Document Object Model
The Virtual DOM in React is a simpler and faster version of the Real DOM. As we all know that, updating the Real DOM can be slow but the Virtual DOM, only updates the changed part of an object, not the whole thing. This makes it much quicker and more efficient as compared to other frameworks.
How Do Virtual DOM And React DOM Interact With Each Other?
When something is updated in a React application, the Virtual DOM (VDOM) gets updated first. It then checks what has changed by comparing the new state with the previous one. After that, it updates only the parts in real DOM that have actually changed, instead of updating everything. This makes the app run faster, especially compared to other front-end technologies that update all parts of the web page even if only one small part has changed.
3. Architecture of React
The architecture of React JS follows a pattern called MVC, which stands for Model-View-Controller. Let us understand what MVC is:
- Model is where all the data of the application is stored.
- View is what the user sees on the screen, it is basically the user interface with which users interact.
- Controller is like a middleman that connects the Model and View part of the application.
In React, the focus is on the “View” part. React helps in creating the user interface (UI) that people interact with.
4. Extensions
React JS has plenty of extensions. These are basically extra tools that can be added to React to make it more powerful and effecient. The example of some popularly used react extension include:
- React Router- It basically helps in managing different web pages in a web application
- Redux- Redux is used for managing data in large applications.
5. Data Binding
Data binding in React JS is the way data flows between the user interface (UI) and the data model. React uses something called “one-way data binding.” This means that data flows in one direction from the data model to the UI. It keeps the data flow simple and easy to manage.
6. Debugging Extension
Facebook has developed special tool called React Developer Tools that helps in finding and fixing errors. This tool is available as a browser extension. It makes debugging, or finding and fixing problems in your code, much easier. You can see the components of your app, inspect them, and understand how they are connected.
7. Components of React
In React JS, everything is built using components. Components are like basic building blocks of the react application. Each part of a webpage like a button, form, or menu is a component in itself. These components are reusable, which means you can use the same button or form in different parts of your app without rewriting the code.
There are two main types of components in React: Functional Components and Class Components. Let’s explore both with simple examples.
Functional Components
A Functional Component is a simple JavaScript function. That receives data and returns a part of the user interface. Functional Components are easy to write and understand. A simple example of a Functional Component is written below for your reference:
| Functional Components Example |
| import React from “react”;
function FunctionalComp() { return <p> PW Skills Example For Functional Component</p>; } export default FunctionalComp; |
Let us understand what is happening in the code above:
- “FunctionalComp” is the name of the component.
- It returns a paragraph (<p>) with the text “PW Skills Example For Functional Component”.
- This component is exported so it can be used in other parts of the application.
Class Components
Class Components basically use JavaScript to create a component. They are powerful and can do more complex tasks, but they are often being replaced by Functional Components in many projects because Functional Components are simpler and easier to work with. An example of a Class Component is given below for your better understanding of concept-
| Example Of Class Component |
| import React from “react”;
export class ClassComp extends React.Component { render() { return <p>PW SKills Example For Class Component </p>; } } export default ClassComp; |
Let us understand the step-by-step explanation of the above code to understand how it Works-
- ClassComp is the name of the component.
- It extends React.Component, which is a part of the React library.
- The render() method is used in this component to return a paragraph (<p>) with the text “PW Skills Example For Class Component”.
- This component is also exported for use in other parts of the application.
Combining Of Different Components
As we have seen above, how different components are mode and exported so that it can be used further in applications. Now, let us see an example to help you understand how these components are grouped together in a single code-
| Combining Of Different Components |
| import React from “react”;
import FunctionalComp from “./Components/FunctionalComp”; import ClassComp from “./Components/ClassComp”; function App() { return ( <div> <h1>Hello! Welcome to PW Skills </h1> <FunctionalComp /> <ClassComp /> </div> ); } export default App; |
Core Concepts In React JS
React is a popular JavaScript library used to build user interfaces, especially for web applications. Understanding the core concepts of React is important if you want to create interactive and dynamic websites. Let’s go over some of these core concepts.
1. Props
Props are like special containers where we store different information we want to pass to a React component. When we create a React component, we might want that component to have different values based on where it’s used. Props allow us to send these values into the component. Let us understand this more clearly with the help of an example
| Props Example |
| function Greeting(props) {
return <h1>Hello, {props.name}!</h1>; } // Using the Greeting component with a prop <Greeting name=”Sahil” /> |
In this example, name=”Sahil” is the prop, and it tells the Greeting component to display “Hello, Sahil!”. Similarly based on different values of prop, greeting component will display different message.
State
State is a special place where a React component can store data that can change over time. Unlike props, which are passed from outside the component, state is managed inside the component. State is important because it allows components to keep track of information that might change with time. When the state changes, the component updates what it shows on the screen automatically. Let us understand this more clearly with the help of a simple example-
| Example Of State |
| import React, { useState } from ‘react’;
function Counter() { const [count, setCount] = useState(0); return ( <div> <p>You clicked {count} times</p> <button onClick={() => setCount(count + 1)}> Click me </button> </div> ); } |
In this example, `count` is a piece of state, and `setCount` is the function that we use to change the value of `count`. Every time the button is clicked, the value of `count` increases by one.
Lifecycle Methods
Lifecycle methods are special functions that run at specific times in a React component’s life. These methods are used to perform certain actions at a particular time. For example, you may want to fetch data from a server when a component appears on the screen or wanted to clean up things when the component is about to disappear. There are various methods used in this lifecycle function, each method has a different task to perform, some of the common methods include:
- componentDidMount: Runs after the component is added to the page.
- componentDidUpdate: Runs every time the component updates
- componentWillUnmount: Runs right before the component is removed from the page.
React JS Advantages And Limitations
React is a popular framework among developers being known for its plenty of advantages and features. Let us look into some popular React JS advantages and limitations to understand what this framework has to offer you and what are its shortcomings.
Advantages:
- It uses a special JavaScript feature called the virtual DOM. This makes the app run faster because the virtual DOM is quicker than the regular DOM.
- It works well with different systems and can be used on both the client and server sides, which is a great benefit.
- By breaking down larger apps into components, it helps in making them easier to manage and understand.
Limitations:
- React JS only focuses on the application’s user interface, so you’ll need other tools if you want a complete set of development tools.
- It uses inline scripting and JSX, which some developers might find difficult or uncomfortable to use.
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React JS FAQs
What are components in React?
Components are the building blocks of a React application. They are reusable pieces of code that return a React element. Components can be either class-based or functional. They allow you to split the UI into independent, reusable pieces that can be managed separately.
What is the difference between props and state?
Props are used to pass data from one component to another. They cannot be changed by the receiving component. State, on the other hand, is used to manage data within a component that can change over time. Unlike props, state is mutable and can be updated using the setState method.
What are lifecycle methods in React?
Lifecycle methods are special functions in class components that are called at different stages of a component’s life, such as when it is created, updated, or removed from the UI. Common lifecycle methods include componentDidMount, componentDidUpdate, and componentWillUnmount.
