In this blog, we will learn how to combine components to make the app easier to maintain. This approach allows to update and change your components without affecting the rest of the page.

Stateless Example

Our first component in the following example is App. This component is owner of Header and Content. We are creating Header and Content separately and just adding it inside JSX tree in our App component. Only App component needs to be exported.
App.jsx

import React from 'react';

class App extends React.Component {
render() {
return (
<div>
<Header/>
<Content/>
</div>
);
}
}
class Header extends React.Component {
render() {
return (
<div>
<h1>Header</h1>
</div>
);
}
}
class Content extends React.Component {
render() {
return (
<div>
<h2>Content</h2>
<p>The content text!!!</p>
</div>
);
}
}
export default App;

To be able to render this on the page, we need to import it in main.js file and call reactDOM.render(). We already did this while setting the environment.
main.js

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.jsx';

ReactDOM.render(<App />, document.getElementById('app'));

The above code will generate the following result.

Stateful Example

In this example, we will set the state for owner component (App). The Header component is just added like in the last example since it doesn’t need any state. Instead of content tag, we are creating table and tbody elements, where we will dynamically insert TableRow for every object from the data array.
It can be seen that we are using EcmaScript 2015 arrow syntax (=>) which looks much cleaner than the old JavaScript syntax. This will help us create our elements with fewer lines of code. It is especially useful when we need to create a list with a lot of items.
App.jsx

import React from 'react';

class App extends React.Component {
constructor() {
super();
this.state = {
data: 
[
{
"id":1,
"name":"Foo",
"age":"20"
},
{
"id":2,
"name":"Bar",
"age":"30"
},
{
"id":3,
"name":"Baz",
"age":"40"
}
]
}
}
render() {
return (
<div>
<Header/>
<table>
<tbody>
{this.state.data.map((person, i) => <TableRow key = {i} 
data = {person} />)}
</tbody>
</table>
</div>
);
}
}
class Header extends React.Component {
render() {
return (
<div>
<h1>Header</h1>
</div>
);
}
}
class TableRow extends React.Component {
render() {
return (
<tr>
<td>{this.props.data.id}</td>
<td>{this.props.data.name}</td>
<td>{this.props.data.age}</td>
</tr>
);
}
}
export default App;

main.js

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.jsx';

ReactDOM.render(<App/>, document.getElementById('app'));

Note − Notice that we are using key = {i} inside map() function. This will help React to update only the necessary elements instead of re-rendering the entire list when something changes. It is a huge performance boost for larger number of dynamically created elements.

So, this brings us to the end of blog. This Tecklearn ‘Environment Setup for ReactJS’ blog helps you with commonly asked questions if you are looking out for a job in React JS and Front-End Development. If you wish to learn React JS and build a career in Front-End Development domain, then check out our interactive, React.js with Redux Training, that comes with 24*7 support to guide you throughout your learning period.

React.js with Redux Training

About the Course

Tecklearn’s React JS Training Course will help you master the fundamentals of React—an important web framework for developing user interfaces—including JSX, props, state, and events. In this course, you will learn how to build simple components & integrate them into more complex design components. After completing this training, you will be able to build the applications using React concepts such as JSX, Redux, Asynchronous Programming using Redux Saga middleware, Fetch data using GraphQL, perform Testing using Jest, successively Deploy applications using Nginx and Docker plus build Mobile applications using React Native. Accelerate your career as a React.js developer by enrolling into this React.js training.

Why Should you take React.js with Redux Training?

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• React Native Supports Cross-platform Development (iOS and Android), and it can reduce the development effort by almost 50% without compromising quality or productivity
• Currently, React JS is being used by major companies like Walmart, Netflix, and HelloSign.

What you will Learn in this Course?

Introduction to Web Development and React.js
• Fundamentals of React
• Building Blocks of Web Application Development
• Single-page and Multi-page Applications
• Different Client-side Technologies
• MVC Architecture
• Introduction to React
• Installation of React
• JSX and its use case
• DOM
• Virtual DOM and its working
• ECMAScript
• Difference between ES5 and ES6
• NPM Modules

Components, JSX & Props
• React Elements
• Render Function
• Components
• Class Component
• Thinking In Components
• What Is JSX
• JSX Expressions
• Creating Your First Component
• Functional Components

React State Management using Redux
• Need of Redux
• Redux Architecture
• Redux Action
• Redux Reducers
• Redux Store
• Principles of Redux
• Pros of Redux
• NPM Packages required to work with Redux
• More about react-redux package
React & Redux
• The React Redux Node Package
• Provider Component
• Connecting React Components with Redux Store
• Reducer Composition
• Normalization: Points to Keep in Mind When Designing a Redux Store
• Redux Middleware

React Hooks
• Caveat of JavaScript classes.
• Functional components and React hooks
• What are React hooks?
• Basic hooks
• useState() hook
• How to write useState() hook when state variable is an array of objects
• useEffect() hook
• Fetch API data using useEffect() hook
• useContext() hook
• Rules to write React hooks
• Additional hooks
• Custom hooks

Fetch Data using GraphQL
• What is GraphQL?
• Cons of Rest API
• Pros of GraphQL
• Frontend backend communication using GraphQL
• Type system
• GraphQL datatypes
• Modifiers
• Schemas
• GraphiQL tool
• Express framework
• NPM libraries to build server side of GraphQL
• Build a GraphQL API
• Apollo client
• NPM libraries to build client side of GraphQL
• How to setup Apollo client

React Application Testing and Deployment
• Define Jest
• Setup Testing environment
• Add Snapshot testing
• Integrate Test Reducers
• Create Test Components
• Push Application on Git
• Create Docker for React Application

Introduction to React Native
• What is React Native
• Use of JSX elements With React Native
• The anatomy of a React Native application
• React Native installation and setup
• Running the app on Android Simulator and Android Device
• Working with Styles and Layout
• Connecting React Native to Redux

React with Redux Projects

Got a question for us? Please mention it in the comments section and we will get back to you.

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