React tutorial for beginners ⚛️

Summary

This video tutorial offers an introduction to ReactJS, a popular JavaScript library for building user interfaces. It explains that React uses components, similar to Lego blocks, to construct web applications. The video covers the basics of JSX, a syntax extension that allows HTML-like code within JavaScript files, and the concept of the virtual DOM for efficient rendering. The tutorial guides viewers through installing Node.js, setting up a React project, and creating simple components like Header, Footer, and a Food list. It also touches on project structure, including the roles of 'node_modules', 'public', and 'src' folders, and demonstrates how to use and reuse components within a React application.

Takeaways

• 😀 React is a JavaScript library for building user interfaces, not a framework.
• 🔧 Components in React are reusable sections of code, akin to Legos, that can be assembled to form complex web applications.
• 📝 JSX, or JavaScript XML, is a syntax extension that allows writing HTML-like code within JavaScript files.
• 🌐 The Virtual DOM in React is a lightweight representation of the real DOM, enabling efficient updates by only applying changes to the real DOM when necessary.
• 🛠️ Prerequisites for starting with React include knowledge of JavaScript, HTML, and CSS, as well as familiarity with ES6 features like arrow functions.
• 💻 Node.js is required for React development, providing a backend JavaScript runtime environment and the Node Package Manager (npm).
• 📂 The project structure of a React application includes folders like 'node_modules' for external libraries, 'public' for public assets, and 'src' for source code.
• 🔄 To create a new React project, use the `npm create vite@latest` command, which sets up a development environment with a modern toolchain.
• 🔗 Components are imported and used within other components by referencing them within the return statement, allowing for a modular and maintainable codebase.
• ⚙️ React components can contain both JavaScript logic and HTML structure, and can be styled with CSS, either through dedicated stylesheets or inline styles.

Q & A

What is ReactJS?

ReactJS is a JavaScript library used to build and arrange user interfaces for web applications. It focuses on creating web applications using components, which are reusable building blocks of code.

What is a component in React?

A component in React is a self-contained section of code that functions as a reusable building block, similar to Legos, where each Lego represents a section of reusable JavaScript and HTML code.

What is JSX and how is it used in React?

JSX is a syntax extension of JavaScript known as JavaScript XML. It allows you to write HTML-like code within your JavaScript files, making it easier to integrate HTML with React components.

What is the Virtual DOM and why is it used in React?

The Virtual DOM is a lightweight version of the real DOM of a web page. It helps keep track of changes made to it, and only applies those specific changes to the real DOM without needing to refresh the entire web page, reducing rendering performance overhead.

What are the prerequisites for learning React?

To learn React, you should know JavaScript, including arrays, classes, objects, and ES6 features like arrow functions. HTML is also mandatory since React components involve rendering HTML elements.

How do you install Node.js and why is it necessary for React?

Node.js can be downloaded from nodejs.org. It is necessary for React because it provides a backend JavaScript runtime environment and includes the Node Package Manager (npm), which is used to manage packages and dependencies for React projects.

What is a text editor and why is it needed for React development?

A text editor is a program used for editing plain text files. For React development, a text editor like Visual Studio Code (VS Code) is recommended as it provides features that aid in coding, such as syntax highlighting and debugging tools.

How do you create a new React project using npm?

To create a new React project, you use the command `npm create vite@latest` in the terminal or command prompt within your project folder. This command sets up a new React project with a development server.

What is the purpose of the 'node_modules' folder in a React project?

The 'node_modules' folder contains external libraries and packages that the React project relies on, including build tools, utility libraries, and routing libraries.

What is the role of the 'public' folder in a React application?

The 'public' folder in a React application contains public assets such as fonts, images, and videos that are not bundled during the final output and are typically available via a URL.

How do you create a new component in React?

To create a new component in React, you create a new .jsx file, define a function with the name of the component, and export it using `export default`. Within this function, you can return a combination of JavaScript and HTML to define the component's structure.

Outlines

00:00

🚀 Introduction to ReactJS

The video introduces ReactJS as a JavaScript library for building user interfaces, emphasizing its component-based architecture. Components are likened to Legos, reusable sections of code that can be assembled into complex structures. React uses JSX, an extension of JavaScript that allows HTML-like code to be written within JavaScript files. It also employs a virtual DOM for efficient rendering updates. The video outlines the prerequisites, including knowledge of JavaScript, HTML, and CSS, and provides a brief overview of the installation process for Node.js and setting up a React project using the 'npm create vite@latest' command.

05:01

🛠 Setting Up the React Environment

The tutorial continues with instructions for setting up the React development environment. It details the installation of Node.js, the use of a text editor like VS Code, and the creation of a project folder. The video demonstrates how to initiate a new React project using the terminal and npm, and how to start the development server. It also explains the project structure, including the roles of the 'node_modules', 'public', and 'src' folders, and the importance of files like 'index.html' and 'package.json'.

10:04

🏗 Building React Components

The presenter guides viewers through creating and structuring React components. It covers the creation of a 'Header' component, explaining how to write a function-based component, export it for use elsewhere, and return a combination of JavaScript and HTML. The video also shows how to import and use this component within the 'App' component. It further demonstrates adding elements like navigation links and a horizontal rule to the 'Header' component, and how to style them using CSS.

15:07

🔗 Component Reusability and Dynamic Content

This section delves into the reusability of React components, showing how to create a 'Footer' component and dynamically insert the current year using JavaScript. It also covers creating a 'Food' component, demonstrating the use of variables and methods within the return statement to display a list of foods. The video highlights the flexibility of component arrangement and the ability to reuse components in various configurations to alter the layout and style of the web application.

20:07

🌟 Wrapping Up the React Introduction

The video concludes with a summary of the key concepts introduced, emphasizing the importance of component-based development in React. It reiterates that components are small, reusable pieces of code that can include both JavaScript and HTML, and that functions return this code to make it reusable. The tutorial serves as a foundational introduction to React, setting the stage for more advanced topics and component usage.

Keywords

💡ReactJS

ReactJS is a JavaScript library for building user interfaces, particularly for single-page applications. It allows developers to create reusable UI components. In the video, ReactJS is introduced as the main topic, and the script discusses its features and how to get started with it.

💡Components

In ReactJS, a component is a self-contained section of code that represents a reusable building block. Components can be thought of as the Lego blocks of React, where each block is a piece of UI that can be used to build a larger application. The script uses the analogy of Legos to explain how components can be combined to create complex web applications.

💡JSX

JSX, or JavaScript XML, is a syntax extension for JavaScript that allows HTML-like code to be written within JavaScript files. This enables developers to mix HTML with JavaScript, making it easier to create React components. The script mentions JSX as a key feature of React, allowing for the creation of components that include both HTML and JavaScript.

💡Virtual DOM

The Virtual DOM is a programming concept where an in-memory representation of the DOM is kept and synced with the real DOM. React uses the Virtual DOM to optimize performance by only updating the parts of the web page that have changed, rather than refreshing the entire page. The script explains how React utilizes the Virtual DOM to enhance rendering performance.

💡Node.js

Node.js is a JavaScript runtime that allows JavaScript to be run on the server-side, outside of the browser. In the context of the video, Node.js is necessary for setting up the development environment for React applications. The script includes instructions on how to download and install Node.js.

💡npm

npm stands for Node Package Manager, which is a tool that comes with Node.js. It is used to manage packages and dependencies for JavaScript projects. The script provides instructions on using npm to create a new React project and to start the development server.

💡Vite

Vite is a build tool that simplifies the process of setting up a modern web development environment. It is used as an alternative to 'create-react-app' and is mentioned in the script as a tool for creating a new React project quickly and efficiently.

💡ES6

ES6, or ECMAScript 2015, is a version of the JavaScript language that introduced several new features, including arrow functions, classes, and modules. The script mentions that knowledge of ES6 features is necessary for working with React, as these features are commonly used in React components.

💡CSS

Cascading Style Sheets (CSS) is used for styling web pages. In the video, CSS is mentioned as a mandatory skill for working with React, as React components often involve rendering HTML elements with applied styles. The script also discusses how CSS can be applied to React components.

💡Project Structure

The project structure refers to the organization of files and folders in a software project. The script provides an overview of the typical structure of a React project, including the 'node_modules' folder, 'public' folder, 'src' folder, and 'package.json' file, explaining the purpose of each component of the structure.

💡Component Reusability

Component reusability is a core concept in React where components are designed to be used multiple times throughout an application. The script demonstrates how to create a reusable component and how it can be included in different parts of the application to build the UI.

Highlights

React is a JavaScript library for building user interfaces, not a framework.

React focuses on components, which are reusable building blocks of code.

Components are analogous to Legos, representing sections of reusable JavaScript and HTML code.

JSX (JavaScript XML) allows writing HTML-like code within JavaScript files.

React utilizes a virtual DOM for efficient tracking and updating of changes in the web page.

Knowledge of JavaScript, including ES6 features like arrow functions, is necessary for using React.

HTML is mandatory for rendering HTML elements in React components.

Node.js is required for React development, providing a backend JavaScript runtime environment.

VS Code is recommended as the text editor for React development.

The project folder is created on the desktop for convenience.

NPM (Node Package Manager) is used for managing project dependencies.

Create React App is used for setting up the React development environment.

The project structure includes node_modules, public, and source folders.

The public folder contains public assets like images and fonts that are not bundled.

The source folder is where most development work occurs, including creating React components.

Components can have dedicated stylesheets for styling.

The main entry point of a React application is the index.html file.

Components are created as functions that return JSX elements.

Components can be imported and used within other components to build the UI.

JSX elements must be wrapped in an enclosing tag, such as a fragment, when returning multiple components.

React components can include both JavaScript and HTML, making them highly reusable.

The project structure and component reusability are key features of React for efficient web development.

Transcripts

hey what's going on everybody it's your

bro hope you're doing well and in

today's video I'm going to show you

everything you need to know to get

started working with reactjs so why

don't you go ahead and sit back relax

and enjoy the

show react is a JavaScript library not

framework that's used to easily build

and arrange user interfaces for web

applications react focuses on building a

web application using these things

called components a component is a

self-contained section of code that

functions as as a reusable building

block think of Legos you could say a

Lego is similar to react component each

Lego represents a section of reusable

JavaScript and HTML code we can build a

diarama or other complicated structure

from these Legos if we use enough of

them and in the correct places react

uses a syntax extension of JavaScript

known as jsx meaning JavaScript XML jsx

allows you to write HTML like code

within your JavaScript files react also

utilizes a virtual Dom it's a

lightweight version of the real Dom of a

web page we can keep track of any

changes made to the virtual Dom and only

apply that specific change to the real

Dom without needing to refresh the

entire web page only that specific

section this reduces rendering

performance overhead before we do begin

you will need to know JavaScript since

react is a JavaScript library everything

up to arrays classes objects and es6

feature such as Arrow functions will be

necessary HTML will also be mandatory

since our react components involve

rendering HTML elements and applying CSS

I do have full free courses on my

YouTube channel on these topics if you

need to catch up or you need a refresher

so that's a quick overview of react

we'll move on to the installation

instructions next we're going to

download nodejs from this URL nodejs.org

node.js is a backend JavaScript runtime

environment it executes JavaScript code

outside of a web browser we're mostly

interested in the node package manager

that comes with it let's download the

latest version of node.js

open it when the download is

complete select next read the license

agreement yes I did read it that fast

next select a destination folder I'll

keep it as

is you can define a custom setup but

that's outside of the scope of this

tutorial series we'll press next we'll

skip tools for Native modules press next

and

install

then

finish you'll also need a text editor I

recommend vs code since you've made it

this far in my web development series

I'm assuming you already have one

downloaded which you can get from this

site code dovisual studio.com and select

the correct download for your operating

system within VSS code I'm going to

create a project folder let's go to

explore open folder just for convenience

I'll place my project folder on my

desktop

I'll create a new folder I'll name mine

website then we will select this

folder we're going to need to open up

command prompt if you're using Windows

or terminal if you're on Mac you can

also do this within vs code go to the

hamburger menu up top terminal new

terminal we within our website folder we

will type the command npm meaning node

package

manager

create vit at latest meaning latest

version V's a development server it's a

modern replacement to create react app

which is now

outdated hit

enter we'll need a name for this project

a common naming convention for a user's

first react project is my react app

that's a common name that you'll see

enter select a framework using the arrow

keys we can select whatever framework we

would like to use we will select react

hit enter are we going to use typescript

or JavaScript we'll stick with plain

JavaScript all right here are the last

few commands and they are given to us

we'll change the directory to our react

app CD meaning change directory my react

app and that's the name of the folder

where our project is

located npm install that is the second

command the last command is npm runev to

start the development server npm

runev all right so our web server is

found at this address let's copy it then

open up a web browser let's paste that

address and here we are within our

development server this is a sample

project that's given to us it even

includes this little counter

hey this is future bro I was editing

this video and I totally forgot to

mention how you can restart the server

if you close out of it all you got to do

is open up a terminal let's go to

terminal new terminal we have to be sure

that we're within our application folder

I'm going to change my directory by

typing CD the name of the folder my

react

app then npm run Dev to start the

development

server

and let's refresh that yep it seems like

it's working so yes I forgot to mention

that that is all I'm quickly going to

cover the project structure of our react

application we'll begin with the node

modules folder this folder contains

external libraries and packages that our

project relies on a few of which are

build tools utility libraries routing

libraries just to name a few we won't be

spending any time directly in this

folder but you should still be aware

what it's for if it just contains

external libraries and packages that our

project relies on next we have the

public folder the public folder contains

any public assets one of which in here

is a vit image it should be this image

right here this folder can contain

public fonts images videos they're not

bundled during the final output they're

typically available via a URL just to

demonstrate I'm going to delete this

image file and see what

happens yep and that logo is gone so my

v logo was a public asset via a URL and

let's put that

back then we have the source folder

we'll spend 99% of our time within the

source folder we have an assets folder

that can contain images and videos the

assets folder is very similar to the

public folder but files within the

assets folder are bundled during the

final output public assets are not and

they're generally available via a URL my

re act image is within the assets folder

currently we have a main jsx file

remember that jsx is Javascript XML in a

way this functions as our main

Javascript file react works with

components we're adding a single

component an app component which we are

importing so let's take a look at our

app component the app component in this

example you could say is the root

component we have two different

stylesheets a stylesheet for app and we

have an index CSS stylesheet this is the

main CSS file for our application we're

importing this file from our main jsx

file right here so that's the source

folder then we have an index HTML file

this is the main entry point into our

program within the body of our document

we have a development with an ID of root

as well as a script to our main jsx file

a few other things you should know about

is this package Json file Json file

files are structured in key value pairs

this file contains metadata about our

project such as the project name the

version number what build we're using

we're using vit and the react version

number just to name a few all right

everybody so in just a moment we will be

creating our first react component we

already do have one component that is

app right now this is serving as a

sample project for us then we are

importing app to main jsx this is our

main J s x file think of it as the main

JavaScript file we are creating a root

element and including our app component

within our app component we do have a

function delete everything within this

function that should eliminate our

sample

project and we no longer need these

Imports we can delete them

too but you do want to keep this export

statement components can have dedicated

stylesheets which you can see here for

app CSS we are going to delete this

because we no longer need

it we do have an app component that's

going to serve as the root we will add

other components to our app component

our app component ties them all together

to create a new component go to your

Source folder we're going to rightclick

then go to new file we will create a

component for a header the extension is

jsx because it's a JavaScript XML file

we will be working with function based

components we will create a function

with the name of header do pay attention

to the

capitalization then we would like to

export this component so we can import

it elsewhere at the end of this file

type

export default the name of the

component header within our header

function we can write a combination of

JavaScript and HTML

all we're going to do within this

function is return something return

parentheses semicolon within the return

statement you can write pure HTML I will

create a header

element so react components they're only

capable of returning a single element

but you can place children elements

within within our header element I will

create an H1 element with text of my

website just to be sure everything is

working let's save I'm holding contrl s

on Windows we will go to our app

component then import the header

component So within app we will type the

statement import the name of the

component

header from a location that location is

going to be do SL header.

jsx we can now use this header component

within our app component we will also be

returning something so we will need a

return statement return parentheses

semicolon what are we going to return I

would like to use my header component so

to add a component we need a set of

angle brackets then type the name of the

component

header like this they're a pair of two

and the second one is closed that's why

we have a forward slash preceding it we

now have a header component you can

shorten the syntax as well take your

component end it with the forward slash

that also works too it's a shorthand way

of writing the same thing let's head

back to our header component We'll add a

few more

elements after our H1 element let's

create a navigation

element then within the navigation

element we'll create an unordered

list within the unordered list we'll

create a few list

items the first will be

home these are list items you would

typically see for a navigation bar

home

about

services and

contact we now have our unordered list

I'll enclose our list items within

anchor tags to make them

hyperlinks a hre equals

I don't want these to go anywhere I'm

just going to leave these empty I'll add

a pound

sign and then be sure to close these

anchor

tags we'll place our text within the

anchor tag so they are now hyperlinks

okay let's do that for the other list

items there we are then after my

navigation element I will add a

horizontal rule to make it look

nice okay there is our header component

we no longer need to work with this

header component we do have some styling

already applied those Styles can be

found within index.css if you would like

to start fresh and eliminate all of

these Styles you can delete everything

from here then you do have HTML with no

CSS in a future video I'll show you

various ways in which we can apply CSS

to a react component but for now we'll

just keep this the same our head element

is now complete we will create a new

element for a footer again go to our

source folder right click go to new

file

footer.

jsx we are creating a function based

component it's a function that's going

to return a footer

component then at the end of our script

we will export default the name of the

component footer so that we we can

import it elsewhere our footer is going

to return something so we need a return

statement then within the set of

parentheses we can return a single

element we will return a footer

element but remember you can place

children elements within an element it

still only counts as one then so what do

we want to do for our

footer I'll include a paragraph

element

within the paragraph element I'm going

to add a copyright symbol to add a

copyright Mark Type ampersand copy semi

call

in then afterwards I'll add your website

name all right now we need to import

this footer going back to our app

component we will

import

footer from footer.

jsx then I would like to include a

footer component after the

header now pay attention to

this we're returning two

components we have this warning we only

have the capability of returning a

single component that's how our return

statements are designed jsx elements

must be wrapped in an enclosing tag do

you want a jsx fragment so since we only

have the capability of returning a

single enclosing tag we're we're going

to enclose our components with what's

known as a

fragment it's just an empty set of anle

brackets so we will enclose all

components within a

fragment and that should work we have

our footer component following our

header component we have our

header and our footer let's make a few

more changes to our

footer I'm going to zoom out a little

bit within our return statement we can

insert some Javas script to insert some

JavaScript you need a set of curly

braces I will create a new date object

this is some JavaScript code

new date parentheses I would just like

the year I will follow this object with

get full year method let's save and take

a look so I'm filming this video near

the end of 2023 your web application

should return the current year when ever

you're watching this all right our

footer component is now

done I'm going to create a component for

a unordered list to sandwich between our

header and our footer I'll create a

component for food we will go to our

source folder create a new file this

component will be food.

jsx again we are creating a function

based component with the name of

food then we will export this component

when we're done export default

food be sure to add a return

statement before we add anything to the

return statement I will create some

JavaScript variables so normally if

you're adding JavaScript code within the

return statement you need a set of curly

braces but outside of the return

statement you don't I will create two

JavaScript constants const food one pick

some food for me I will pick an

orange let's make that

Capital all right then let's create a

second food

variable food 2 for me will be a

banana within the return statement we

can utilize these

constants what do we want to return

exactly I will return an unordered

list we'll have a few list

items three to be

exact my first list item I'll just add

some text I'll add an

apple just to be sure that everything is

working let's import this food component

from our app

component again we need an import

statement import food from food. jsx we

can now use the food component we will

add that after the header we will add

food then here is our first list item an

apple okay let's head back to our food

component for our second list item I

will add food one that's our constant

now pay attention to this if I type food

one well we're literally printing the

text food one since we're within our

return statement I would like to include

some JavaScript code we're including a

JavaScript variable so I need to enclose

this variable within a set of curly

braces because we're within the return

statement and now now my second list

item is an orange then let's include

food 2 but I'm going to add one more

thing food 2 however I'm going to use

the builtin 2 uppercase method just to

demonstrate that we can use JavaScript

functions all right and there is our

unordered list we have an apple orange

and a

banana so these components are now

complete and the cool thing about react

as well is that we can keep on reusing

these components if we would like I

would like a couple food components so I

will just paste another component we now

have two food components or even three

or

four you can rearrange these components

however you would like by rearranging

them we can change the feel and style of

our web application for demonstration

purposes I will put our footer on the

top that doesn't make any sense but I

just want to demonstrate so our footer

is now on the top followed by the header

then the food component or maybe I would

like the food component on top

we now have our food component footer

component then our header

component all right everybody that is an

introduction to react react is all about

reusing components a component is a

small section of code that can include

JavaScript and HTML your function will

return that code and make it reusable

and that is your introduction to

react