javascript full guid

JavaScript is a dynamically typed language. Because data type will automatically assigned at the time of compilation or code execution.

Jb b ap function return kra gha to variable ma store kra sakty ha sirf console log say ni kr sakty

return

//datatypes are based on memory allocation
Primitive datatypes->  call by value (string,number,boolean,null,undefined,BigInt,symbol) ->Stack memory

Reference/Non primitive data types -> call by reference ( array,object, function) -> heap memory

JavaScript is a dynamically typed language. This means that you don't need to specify the data type of a 
variable when you declare it.

01_variables.js

const accountId = 144553
let accountEmail = "hitesh@google.com"
var accountPassword = "12345"
accountCity = "Jaipur"
let accountState;

// accountId = 2 // not allowed


accountEmail = "hc@hc.com"
accountPassword = "21212121"
accountCity = "Bengaluru"

console.log(accountId);

/*
Prefer not to use var
because of issue in block scope and functional scope
*/


console.table([accountId, accountEmail, accountPassword, accountCity, accountState])

02_dataTypes.js

"use strict"; // treat all JS code as newer version

// alert( 3 + 3) // we are using nodejs, not browser

console.log(3 
    +
     3) // code readability should be high

console.log("Hitesh")


let name = "hitesh"
let age = 18
let isLoggedIn = false
let state;

// number => 2 to power 53
// bigint
// string => ""
// boolean => true/false
// null => standalone value
// undefined => 
// symbol => unique


// object

console.log(typeof undefined); // undefined
console.log(typeof null); // object

03_conversionOperation.js

let score = "hitesh"

//console.log(typeof score);
//console.log(typeof(score));

let valueInNumber = Number(score)
//console.log(typeof valueInNumber);
//console.log(valueInNumber);


// "33" => 33
// "33abc" => NaN
//  true => 1; false => 0

let isLoggedIn = "hitesh"

let booleanIsLoggedIn = Boolean(isLoggedIn)
//  console.log(booleanIsLoggedIn);

// 1 => true; 0 => false
// "" => false
// "hitesh" => true

let someNumber = 33

let stringNumber = String(someNumber)
// console.log(stringNumber);
// console.log(typeof stringNumber);

// *********************** Operations ***********************

let value = 3
let negValue = -value
// console.log(negValue);

// console.log(2+2);
// console.log(2-2);
// console.log(2*2);
// console.log(2**3);
// console.log(2/3);
// console.log(2%3);

let str1 = "hello"
let str2 = " hitesh"

let str3 = str1 + str2
// console.log(str3);

// console.log("1" + 2);
// console.log(1 + "2");
// console.log("1" + 2 + 2);
// console.log(1 + 2 + "2");

// console.log( (3 + 4) * 5 % 3);

// console.log(+true);
// console.log(+"");

let num1, num2, num3

num1 = num2 = num3 = 2 + 2

let gameCounter = 100
++gameCounter;
console.log(gameCounter);

// link to study
// https://tc39.es/ecma262/multipage/abstract-operations.html#sec-type-conversion

04_comparision.js

// console.log(2 > 1);
// console.log(2 >= 1);
// console.log(2 < 1);
// console.log(2 == 1);
// console.log(2 != 1);


// console.log("2" > 1);
// console.log("02" > 1);

console.log(null > 0);
console.log(null == 0);
console.log(null >= 0);

console.log(undefined == 0);
console.log(undefined > 0);
console.log(undefined < 0);

// === 

console.log("2" === 2);

datatypes-summary.js

//  Primitive

//  7 types : String, Number, Boolearn, null, undefined, Symbol, BigInt

const score = 100
const scoreValue = 100.3

const isLoggedIn = false
const outsideTemp = null
let userEmail;

const id = Symbol('123')
const anotherId = Symbol('123')

console.log(id === anotherId);

// const bigNumber = 3456543576654356754n



// Reference (Non primitive)

// Array, Objects, Functions

const heros = ["shaktiman", "naagraj", "doga"];
let myObj = {
    name: "hitesh",
    age: 22,
}

const myFunction = function(){
    console.log("Hello world");
}

console.log(typeof anotherId);

// https://262.ecma-international.org/5.1/#sec-11.4.3

data type typeof operator

Thank you sir for your guidance and hard work here is your gift 

* Premitive Datatypes

                  Type                                   typeof

i)             Number                               number
ii)            String                                   string
iii)           Boolean                               boolean
iv)           Bigint                                   bigint
v)            Symbol                                symbol
vi)           Null                                      object
vii)          Undefined                           undefined


* Non-Premitive OR Referance OR Object datatype

                  Type                                   typeof

i)               Object                                object
ii)              Array                                  object
iii)             Function                            function(object)

This is my research and output if anythig is wrong please feel proud to reply me 

Stack and Heap memory in javascript

let youtubename="Developer";
let myname=youtubename;
myname="Website";
console.log(youtubename);
console.log(myname);

**************************************************************
let userone={
    name:"ALI",
    age:21
}
let usertwo=userone;
usertwo.name="RAO";
console.log(userone.name);
console.log(usertwo.name);

05_strings.js

const name = "hitesh"
const repoCount = 50

// console.log(name + repoCount + " Value");

console.log(`Hello my name is ${name} and my repo count is ${repoCount}`);

const gameName = new String('hitesh-hc-com')

// console.log(gameName[0]);
// console.log(gameName.__proto__);


// console.log(gameName.length);
// console.log(gameName.toUpperCase());
console.log(gameName.charAt(2));
console.log(gameName.indexOf('t'));

const newString = gameName.substring(0, 4)
console.log(newString);

const anotherString = gameName.slice(-8, 4)
console.log(anotherString);

const newStringOne = "   hitesh    "
console.log(newStringOne);
console.log(newStringOne.trim());

const url = "https://hitesh.com/hitesh%20choudhary"

console.log(url.replace('%20', '-'))

console.log(url.includes('sundar'))

console.log(gameName.split('-'));

JavaScript String Methods

06_nums_and_math.js

const score = 400
// console.log(score);

const balance = new Number(100)
// console.log(balance);

// console.log(balance.toString().length);
// console.log(balance.toFixed(1));

const otherNumber = 123.8966

// console.log(otherNumber.toPrecision(4));

const hundreds = 1000000
// console.log(hundreds.toLocaleString('en-IN'));

// +++++++++++++ Maths +++++++++++++++++++++++++++++

// console.log(Math);
// console.log(Math.abs(-4));
// console.log(Math.round(4.6));
// console.log(Math.ceil(4.2));
// console.log(Math.floor(4.9));
// console.log(Math.min(4, 3, 6, 8));
// console.log(Math.max(4, 3, 6, 8));

console.log(Math.random());
console.log((Math.random()*10) + 1);
console.log(Math.floor(Math.random()*10) + 1);

const min = 10
const max = 20

console.log(Math.floor(Math.random() * (max - min + 1)) + min)

02_basics

01_arrays.js

// array

const myArr = [0, 1, 2, 3, 4, 5]
const myHeors = ["shaktiman", "naagraj"]

const myArr2 = new Array(1, 2, 3, 4)
// console.log(myArr[1]);

// Array methods

// myArr.push(6)
// myArr.push(7)
// myArr.pop()

// myArr.unshift(9)
// myArr.shift()

// console.log(myArr.includes(9));
// console.log(myArr.indexOf(3));

// const newArr = myArr.join()

// console.log(myArr);
// console.log( newArr);


// slice, splice

console.log("A ", myArr);

const myn1 = myArr.slice(1, 3)

console.log(myn1);
console.log("B ", myArr);


const myn2 = myArr.splice(1, 3)
console.log("C ", myArr);
console.log(myn2);

02_array.js

const marvel_heros = ["thor", "Ironman", "spiderman"]
const dc_heros = ["superman", "flash", "batman"]

// marvel_heros.push(dc_heros)

// console.log(marvel_heros);
// console.log(marvel_heros[3][1]);

// const allHeros = marvel_heros.concat(dc_heros)
// console.log(allHeros);

const all_new_heros = [...marvel_heros, ...dc_heros]

// console.log(all_new_heros);

const another_array = [1, 2, 3, [4, 5, 6], 7, [6, 7, [4, 5]]]

const real_another_array = another_array.flat(Infinity)
console.log(real_another_array);



console.log(Array.isArray("Hitesh"))
console.log(Array.from("Hitesh"))
console.log(Array.from({name: "hitesh"})) // interesting

let score1 = 100
let score2 = 200
let score3 = 300

console.log(Array.of(score1, score2, score3));

04_objects.js

// const tinderUser = new Object()
const tinderUser = {}

tinderUser.id = "123abc"
tinderUser.name = "Sammy"
tinderUser.isLoggedIn = false

// console.log(tinderUser);

const regularUser = {
    email: "some@gmail.com",
    fullname: {
        userfullname: {
            firstname: "hitesh",
            lastname: "choudhary"
        }
    }
}

// console.log(regularUser.fullname.userfullname.firstname);

const obj1 = {1: "a", 2: "b"}
const obj2 = {3: "a", 4: "b"}
const obj4 = {5: "a", 6: "b"}

// const obj3 = { obj1, obj2 }
// const obj3 = Object.assign({}, obj1, obj2, obj4)

const obj3 = {...obj1, ...obj2}
// console.log(obj3);


const users = [
    {
        id: 1,
        email: "h@gmail.com"
    },
    {
        id: 1,
        email: "h@gmail.com"
    },
    {
        id: 1,
        email: "h@gmail.com"
    },
]

users[1].email
// console.log(tinderUser);

// console.log(Object.keys(tinderUser));
// console.log(Object.values(tinderUser));
// console.log(Object.entries(tinderUser));

// console.log(tinderUser.hasOwnProperty('isLoggedIn'));


const course = {
    coursename: "js in hindi",
    price: "999",
    courseInstructor: "hitesh"
}

// course.courseInstructor

const {courseInstructor: instructor} = course

// console.log(courseInstructor);
console.log(instructor);

// {
//     "name": "hitesh",
//     "coursename": "js in hindi",
//     "price": "free"
// }

[
    {},
    {},
    {}
]