Basics Of JS

Arrow functions

const user = {
    username: "hitesh",
    price: 999,

    welcomeMessage: function(){
        console.log(`${this.username}, welcome to website`);
        console.log(this);
    }
}

user.welcomeMessage();
user.username = "Sam";
user.welcomeMessage();

console.log(this);

function chai(){
    let username = "hitesh";
    console.log(this.username);
}

chai();

const chai1 = function (){
    let username = "hitesh";
    console.log(this.username);
}

chai1();

const chai2 = () => {
    let username = "hitesh";
    console.log(this);
}

chai2();

const addTwo = (num1, num2) => {
    return num1 + num2;
}

const addTwo1 = (num1, num2) =>  num1 + num2;
const addTwo2 = (num1, num2) =>  (num1 + num2);
const addTwo3 = (num1, num2) =>  ({username: "hitesh"});;

console.log(addTwo(3, 4));
console.log(addTwo1(3, 4));
console.log(addTwo2(3, 4));
console.log(addTwo3(3, 4));

const myArray = [2, 5, 3, 7, 8];

// myArray.forEach();

Functions

function sayMyName(){
    console.log("H");
    console.log("I");
    console.log("T");
    console.log("E");
    console.log("S");
    console.log("H");
};

sayMyName();

function addTwoNumbers(number1, number2){
    return number1 + number2;
}

const result = addTwoNumbers(3, 5);

console.log("Result: " + result);

function loginUserMessage(username = "sam"){
    if(!username){
        console.log("Please enter a username");
        return;
    }

    return `${username} just logged In`;
}

console.log(loginUserMessage("hitesh"));

function calculatePrice(val1, val2, ...num1){
    return num1;
}

console.log(calculatePrice(300, 500, 600));

const user = {
    username: "hitesh",
    prices: 199
};

const myNewArray = [200, 400, 100, 600];

function returnScondValue(getArray){
    return getArray[1];
}


console.log(returnScondValue(myNewArray));

IIFE

(function chai(){
    console.log('DB CONNECTED!');
})();

((name) => {
    console.log(`DB CONNECTED TWO ${name}`);
})('hitesh');

Scope

let a = 300;
if(true){
    let a = 10;
    const b = 20;
    console.log('INNER: ', a);
}

console.log(a);
// console.log(b);

function one(){
    const username = "hitesh";

    function two(){
        const website = "youtube";
        console.log(website);
    }

    two();
}

one();

if (true) {
    const username = "hitesh"
    if (username === "hitesh") {
        const website = " youtube"
        // console.log(username + website);
    }
    // console.log(website);
}

// console.log(username);

console.log(addone(5));

function addone(num){
    return num + 1;
}


addTwo(4)
const addTwo = function(num){
    return num + 2;
}