Top 9 JavaScript topics to know before learning React JS in 2024

Summary

This video script emphasizes the importance of a solid JavaScript foundation before diving into ReactJS. It outlines nine essential JavaScript topics, including variables, functions, arrays, objects, conditionals, event listeners, callbacks, promises, and async/await, which are crucial for a smooth learning journey in React. The speaker, an experienced React instructor, recommends their free 'Namaste JavaScript' playlist on YouTube for in-depth coverage of these topics, ensuring that learners are well-prepared to master ReactJS and excel as front-end developers.

Takeaways

• 📚 Before learning ReactJS, ensure a solid understanding of HTML, CSS, and JavaScript basics.
• 🔑 Know the fundamentals of JavaScript variables, including let, const, and var.
• 🎯 Grasp the concept of functions, including arrow functions and higher-order functions.
• 🗂️ Understand arrays and objects, including destructuring, rest, and spread operators.
• ✅ Learn conditional rendering with if/else statements and the ternary operator.
• 🔍 Master array operations with map, filter, reduce, and sort functions.
• 🎧 Get familiar with event listeners, event bubbling, and capturing.
• ⏰ Understand setTimeout and setInterval for timing and asynchronous operations.
• 📞 Learn about callbacks, promises, and how to handle API calls.
• 🛠️ Use async/await for a cleaner syntax and better promise handling.
• 🔧 Implement error handling with try/catch for robust application development.

Q & A

What is the most important prerequisite for learning ReactJS according to the speaker?

The most important prerequisite for learning ReactJS is having a solid understanding of HTML, CSS, and JavaScript fundamentals.

How long has the speaker been coding in React?

The speaker has been coding in React for 7 years.

What are the core parts of JavaScript that the speaker emphasizes for ReactJS learning?

The core parts of JavaScript emphasized for ReactJS learning include functions, arrow functions, higher-order functions, and event listeners.

What is the significance of functions in JavaScript and ReactJS?

Functions are the heart of JavaScript and are crucial in ReactJS as they are the building blocks for handling events, making API calls, and managing state.

What are the four ES6 concepts related to arrays and objects that the speaker mentions as essential for JavaScript understanding?

The four ES6 concepts are object destructuring, array destructuring, rest operator, and spread operator.

Why is understanding conditional rendering important in ReactJS development?

Conditional rendering is important in ReactJS development because it allows developers to control the flow of the UI based on certain conditions, which is a common requirement in building dynamic web applications.

What are the array operations that the speaker suggests one should be fluent with in JavaScript for ReactJS development?

The speaker suggests being fluent with map, filter, reduce, and sort functions for array operations in JavaScript, as they are frequently used in ReactJS for handling data.

How does the speaker describe the role of promises in ReactJS development?

The speaker describes promises as a fundamental concept in ReactJS development, especially for making API calls, and emphasizes the importance of understanding them in-depth.

What is the alternative to promises that the speaker recommends learning for modern ReactJS development?

The speaker recommends learning async/await as an alternative to promises, as it provides a cleaner syntax and is widely used in modern ReactJS code.

Why is error handling important when building large-scale web applications with ReactJS?

Error handling is important for building large-scale web applications with ReactJS because it helps developers manage and handle errors effectively, ensuring a more robust and reliable user experience.

What is the speaker's advice for those who want to become ReactJS developers in 2024?

The speaker advises to learn the essential JavaScript topics, such as variables, functions, arrays, objects, conditionals, and error handling, before starting to learn ReactJS, and to choose a learning resource that suits one's needs, whether it's their own course or other available resources.

Outlines

00:00

📚 Essential JavaScript Foundations for ReactJS

The speaker emphasizes the importance of understanding JavaScript basics before diving into ReactJS. They have been coding in React for seven years and teaching for three, noticing that students need a strong foundation in HTML, CSS, and JavaScript. The video aims to cover topics like variables, functions, arrow functions, higher-order functions, arrays, objects, destructuring, rest and spread operators, conditionals, ternary operators, and error handling. The speaker also recommends their 'Namaste JavaScript' playlist for further learning.

05:00

🎥 Understanding Event Listeners and Asynchronous JavaScript

The speaker discusses the necessity of knowing event listeners, such as click and mouse events, and concepts like event bubbling and capturing. They also mention the importance of understanding setTimeout and setInterval for application features. The video touches on callbacks, promises, and async/await for handling API calls and asynchronous operations. The speaker suggests their YouTube channel for in-depth coverage of these topics and encourages learning these concepts for a successful ReactJS journey.

10:01

📈 Promoting the Namaste React Course and Future Content

The speaker promotes their Namaste React course, offering a promo code for special discounts. They express a willingness to cover more topics around React and JavaScript based on viewer comments and encourage engagement for future content. The speaker concludes by providing a link to the course in the video description and thanks the audience for their support.

Keywords

💡ReactJS

ReactJS, often simply referred to as React, is a popular JavaScript library for building user interfaces, particularly for single-page applications. It allows developers to create reusable UI components and manage the state of the application efficiently. In the video, the speaker emphasizes the importance of understanding JavaScript fundamentals before diving into React, as it forms the backbone of React development.

💡JavaScript

JavaScript is a high-level, dynamic, and interpreted programming language that is used extensively for web development. It enables the creation of interactive elements on web pages. The video script highlights that a solid grasp of JavaScript is crucial for learning React, as React is built on top of JavaScript and extends its capabilities.

💡HTML

HTML, or HyperText Markup Language, is the standard markup language for creating web pages and web applications. It provides the basic structure of a webpage. The speaker in the video mentions HTML as a foundational skill necessary for web development and a prerequisite for learning React, as it is part of the technologies that React interacts with.

💡CSS

CSS, or Cascading Style Sheets, is a style sheet language used for describing the look and formatting of a document written in HTML. It allows developers to separate the presentation of a web page from its structure. The video emphasizes CSS as a key component of web development, alongside HTML and JavaScript.

💡Variables

In programming, a variable is a storage location in memory that holds a value. In JavaScript, variables can be declared using 'let', 'const', or 'var'. The video script underscores the importance of understanding how variables work in JavaScript, which is fundamental for React development as React uses state variables to manage UI state.

💡Functions

Functions in JavaScript are blocks of code designed to perform a particular task. They are reusable and can be invoked multiple times. The video highlights functions as the 'heart' of JavaScript and a core part of React, where functions are used to handle UI updates and manage component lifecycles.

💡Arrow Functions

Arrow functions are a concise syntax for writing functions in JavaScript that was introduced in ES6. They provide a shorter syntax and a different 'this' binding scope. The video script mentions arrow functions as an important JavaScript feature that developers should understand before learning React.

💡Higher-Order Functions

Higher-order functions are functions that take other functions as arguments, return a function, or both. They are a powerful concept in JavaScript that allows for more flexible and reusable code. The video emphasizes the importance of understanding higher-order functions in React, where they are often used for handling state and side effects.

💡Arrays and Objects

Arrays and objects are fundamental data structures in JavaScript used to store and manipulate collections of data. The video script stresses the importance of knowing how to work with arrays and objects, including destructuring, rest parameters, and the spread operator, as they are frequently used in React for managing state and props.

💡Conditional Rendering

Conditional rendering in React is the process of displaying different UI components based on certain conditions. It is achieved using JavaScript's conditional operators like 'if', 'else', and the ternary operator. The video highlights the significance of understanding conditional rendering as it is a common practice in React development for creating dynamic user interfaces.

💡Event Listeners

Event listeners in JavaScript are functions that are attached to HTML elements to respond to specific events, such as clicks or key presses. The video script mentions event listeners as a core part of web applications, including React, where they are used to handle user interactions and update the UI accordingly.

Highlights

Knowing JavaScript basics is essential before learning ReactJS.

HTML and CSS are the backbone of all websites.

JavaScript is the major component rendered onto the DOM.

Understanding variables (let, const, var) is fundamental in JavaScript.

Functions are the heart of JavaScript and crucial for React.

Familiarity with arrow functions and higher-order functions is necessary.

Proficiency in handling arrays and objects, including destructuring, rest, and spread operators.

Understanding conditionals (if/else), ternary operators, and logical operators is important.

Mastering array functions like map, filter, reduce, and sort is essential for React development.

Event listeners, event bubbling, and capturing are core concepts for web applications.

Knowing setTimeout and setInterval for application features is required.

Callbacks and promises are vital for API calls in React.

Async/await is a modern syntax for handling promises in React.

Error handling with try/catch is important for production-ready web applications.

ReactJS is the most popular front-end library, and knowing it is in high demand.

The speaker offers a ReactJS course called Namaste React with a promo code for discounts.

The speaker encourages learning from various sources and is open to suggestions for more topics.

Transcripts

before you start learning reactjs you

should definitely know JavaScript you

know it has been 7 years since I'm

coding in react and it has been three

years since I actively teaching react to

students right I have taught a lot of

students and I have observed that uh a

lot of students need to know basics of

HTML CSS and JavaScript before they can

move and start learning react okay so in

this video I will be covering all the

topics that you should know inside

JavaScript before you start learning

react

if you will cover these topics it will

your react Learning Journey will become

very smooth and it will be very helpful

for you and this is the right path to

learn and master reactjs and become a

great front-end developer in 2024 so

basically before you learn react you

should definitely know basics of HTML

and CSS because HTML and CSS is the

backbone of all the websites that you

make right any web app will you make

HTML and CSS are the main things that

will be rendered onto the Dom the major

thing is Javascript right and the major

doubt from the students that I get is

how much JavaScript should I know right

so this video is primarily focusing upon

these JavaScript topics that you should

know before you can start learning

reactjs now let me just cover these

topics one by one and I will tell you

how much should you learn inside these

topics also as I go ahead in this video

I'll start from the basics and we'll

tell you the advanced topics also which

you should know as a uh good react

developer so the first topic over here

is you should know the basics of

JavaScript that is how variables work

right what is a let variable what is a

const variable what is a where variable

right how do you define these variables

how these variables are HED how

variables work right uh you should know

this Basics right and uh you know if you

want to learn this you can just go ahead

and watch out Namaste JavaScript I have

covered all of this the second thing is

you should know about functions right

functions is the heart of JavaScript

functions is is the beautiful thing the

best thing about JavaScript is functions

everything whatever happens inside

JavaScript happens actually inside a

function right so you can't learn

JavaScript without learning functions

and functions are the core part of react

as well now inside functions you have to

note that you should know Arrow

functions right know what is Arrow

functions know the syntax of it you

should be able to write it the second

thing you should know what are higher

order functions right just check what

are higher order functions so if you

want to learn both of them I have also

covered these in my free playlist

Namaste JavaScript on YouTube just go

ahead and check it out in my YouTube

channel now the third thing is arrays

and objects right so a lot of things

that we will do while building an web

app it is about arrays and objects you

cannot avoid arrays and objects if you

are working with react or any web

applications right so you should know

how to do with arrays and objects right

you should know when I say arrays on

objects you should know how d

structuring works right it is an es6

concept note it Down Right destructuring

object destructuring array destructuring

rest operator spread operator right

these four things right you have to be

aware of right you should be able to

deal with arrays so these are the four

things you should know let me repeat it

down object destructuring array

destructuring rest operator spread

operator these four things you should

know you cannot do anything if you don't

know how to deal with Arizon objects in

JavaScript the fourth thing you should

know is if else and conditions right so

basically how do you write if and else

cases in uh JavaScript and then

basically tary operator and the uh

conditional rendering right basically

the and and operator right so basically

it is very important and we use inside

react when we build our projects right

when I was teaching Namaste react I used

a lot of conditional rendering a lot of

people get confused with the syntax when

they see a question mark and a dot dot

right so you should know tary operator

and then uh and and symbol that is the

and operator right uh very important and

the or operator along with these three

things you should also know optional

chaining in JavaScript right now the

fifth thing you should know is map

filter and reduce function along with a

sort function so basically see when you

are dealing with arrays and objects so a

map function a filter or reduce a sort

function is very much right these are

the functions which are given by

JavaScript for array operations right

you cannot avoid it and you know trust

me whenever you are writing react map

function you should you should be able

to write it very fluently right the maap

function in JavaScript uh I have a video

on my Channel about map filter and

reduce go and watch it up right before

you start learning react because that

will help you a lot in your react

Journey the sixth thing that you should

know is event listeners right so learn

about event listeners when I say event

listeners that means click event on

Mouse up event on key down event and all

these events right how does event work

when you click on it how does that event

work right you know there are two

concepts event bubbling and capturing

right so I have made these videos on my

YouTube channel right go ahead search

for event bubbling on YouTube right and

check out my video right that would be

very helpful for you before you start

learning reactjs because events are the

core part of any web application right

you have to write buttons and you have

to click them so you would definitely

need events so you should know events

along with events you should also know

how set time out works right set timeout

set interval because there are a lot of

features that you would build in your

application that would need these kind

of functionalities and you should know

these and all these things are covered

in Namaste JavaScript again so you can

go ahead and check it out over there on

my channel and you know I am not

promoting my videos or Namaste

JavaScript over here it is just that see

everything is available for free on

YouTube learn it from that playlist or

learn it from outside the internet but I

am just honestly telling you that you

would need this if you want to become a

react developer the seventh thing that

you should know is call backs

promises very much right so what is call

backs right I started Namaste JavaScript

season 2 I covered call back call back

hell promises promise functions cover

all of this right without promises you

cannot make API calls right you should

know what is a promise you should know

the in-depth promise right and then

promise apis there are three videos

right I think three or four videos in

which I have covered call back call back

hell promises promise apis right watch

those four videos in Namaste JavaScript

season 2 right uh all these episodes and

it will help you to understand what is

promises without promises right you you

cannot go ahead and learn react because

very important whenever you'll have to

make an API call and get the data you

should know promises in depth that is

very very very important before you

start learning reactjs and when I say

promises that means you should

definitely know how fetch function Works

everything right I have covered

everything in those videos go ahead and

watch those videos the eighth thing that

you should know is async await right I

know that Pro see async await is kind of

like an alternative for promises right

it's a new way of handling promises okay

it's kind of like like a sugar quoting

on top of promises but it's a very good

thing lot of modern react code that we

write uses async await whenever I teach

react to students whenever I take

examples whenever I teach in Namaste

react whenever I build projects I use

asyn AIT asyn aate is a very good syntax

you should definitely know asyn ofate

before you start writing production

ready react code ninth topic is try

catch right yes so try catch is an

important thing you should know when you

are you know when you always are making

an API call or writing an asyn C

function or lot of places right so it is

for error handling error handling is a

major concept whenever you are building

a large scale production ready web

application in react right uh whenever I

was teaching in Namaste react right I

used a lot of TR catch so that I can

catch those errors right I can found

bugs in my API calls and then I can

handle them properly okay so you should

definitely know error handling if you

are going to learn reactjs right so

please please please learn it before you

can go ahead and do that where should

you learn see I have covered a little

bit of TR catch inside my async video

right async C video but but you can also

go ahead and find it out more on the

internet uh I have not made a separate

video on tratch but I already have

covered that in ising so you can go

ahead and watch that video again so

these were the nine topics important

topics that that you should must know

before you start learning reactj if you

know mostly all of them then you can go

ahead and successfully start learning

reactjs time for a promotion right so

basically I also have a reactjs course

which is Namaste react I will give you

the link in the description I have a

promo code which is running up right now

we have special discounts running in you

can learn from there or I'm telling you

that okay if you don't want to learn

from my course it's okay right I am not

here to make this video just to say my

course okay learn it from outside but I

as a teacher want to tell you that if

you are going to learn reactjs in 2024

then definitely you should know these

topics inside JavaScript you know see

wherever you learn from learn and wish

you the best in your career and go ahead

learn it because reactjs is the most

popular front end library right now if

you are a front-end developer if you

know react there's a huge demand of you

in Market okay so go ahead learn it from

wherever you wish to if you want to

check out my course I will give you the

link in the description I have become

active on YouTube once again if you want

me to cover more topics around react

around JavaScript comment down below I'm

looking out for topics from you all and

I will make more such amazing videos for

you all thank you for

[Music]

watching