Event listening in react

 How we can listen to som eevents

some envents fire like click or automatically

user enters into input button , that is event

on word type it is event

responseive

reactive

interactive 

flexible

React add new template part 2

 =

=

must have one parent ellement

     <div>

            <h1>First Component</h1>

            <p>This is the first component</p>

        </div>

import React, { useState } from 'react';

function First(){

   

    return (        

        <div>

            <h1>First Component</h1>

            <p>This is the first component</p>

        </div>

    )

}

export default First;

=

adding styles in jsx 

import './subscription.css';

div className=''

=

=============

dynamic data in jsx react

variables {} 

curly braces

{javascript code valid}

javascript expressions

=

Data passing in react

=

communication between components

pass as prop

let subscription {

{},

{}

}

Accesing props in react

implemetning js code in jsx react

convert date to readable format

creating single responsibilty components in react

component in component

because for date more transformations 

=

=

children props in react

same kind of template in so many places

=

==

other details in jsx react

writing react in  soo many ways

folder staructure

arrow function 

=

what is react

 why react is popular

what are the key functions of react

who can start a career as web developer , ui developer, full stack applicaitons 

component

how to maintain an dpass the data in component

commuinicaion between component

modules what is modules 

what is jsx

how to pass betwen data

simple to learn

waht is react

it is javascript library for building web interfaces

use to buildy higly interactive, flexible, and responsive webinterfaces

interactive -> mobile 

flexible -> page ka breakout nahi, means desktop to mobile at position

responsive => fast,  it will get data from backen but takes speed and 

client side scription 

load the code at browser

it will not load at server

what is spa

this uses dom

like tree

DOM MANIPULATION

--

htmnl dom

why choose react for web development

to render on the scren 

latency decrease

user actiion -> have to react that action

for in javascript -> to write simple action shave to write too much of code

but 

event listener

in javascript we cannot do after event handler calls

but in react we can call that 

in react we can divide the logic into smaller reusable components

component

==

easy to code

easy  to write

easy to understand

realt time example

react vs angular vs vue

in react -> if need any new fatures , u have ot use library

devloping using eract less features , less load on user

less learning time

angular-> so man y features are there which we are not use, heavily loaded

vuejs

setting up project

=

what installations required

visualt studio code 

prettier extension

eslint

auto save in visual studoio 

==

components in react

user given input and output -> interactive user interface

what is rsx

componentns

html,css,javascript basic knowledge

reac is the ligbrary based on the javascript

react js easy to use, code reusability, easy to declare

==

header is one componer

line is one component

pointer is another component

why component sis another component

how do u create component in react

function name an dcomponent must match , maing conventions

write the function in component and export taht

app.js 

import that

=

====

installation of node

node js -> run javascript without browser 

browser hsa capabiltiy when javascript loaded into browser

node js is used by this tool create react app to run some logic

npx create-react-app myfirst app

it willl install react folder, cretre react server

it will install depundencies and abundancies

npm update or install 

to install all the diependices use above

and it will save in  node_modiles

after create react no need to run , npx create it already run the npm install

understanding file staructure

  package.json

after installed u can see bsic files 

package.json

dependecies

scripts

npm start ->

package-lok.json 

information gather, dependices history , from where install whic hversion

and meta data it has

src folder

==

undertand index.js

first file that gets used when u open is indexd.js

where to start the applicaiton 

what is boostrap 

it will there in index.js

it is default file

first file index.html

it will call index.js

imporeted app , app.js is the ocmponent

default react logo will show from app.js

defenelty export

index.js react 

convert to html, javacript

reactdom -> eract dom library

react tdom is used to render something

reactdo.nreder

========================

introduction to jsx

jsx meanss javascript + xml

xml means its one type of html

react juses jsx it is also like html but how its validate

writing html in javascript called jsx

jsx not uneerstad by browser, react will transform itno pure javascript, html, css

mainchunk .js

it has all transformed rect

bundle.js

it has also import no there

pure javascript follows the imperaqtive approach

where u give clear inster

custom components