React tutorial for beginners ⚛️
Summary
TLDRThis 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
🚀 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.
🛠 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'.
🏗 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.
🔗 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.
🌟 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.
Mindmap
Keywords
💡ReactJS
💡Components
💡JSX
💡Virtual DOM
💡Node.js
💡npm
💡Vite
💡ES6
💡CSS
💡Project Structure
💡Component Reusability
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
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