Control Flow

One

const isUserLoggedIn = true;
const temperature =  41;

if(temperature ===  40){
    console.log("Temperature is 40 degrees");
} else {
    console.log("Temperature is not 40 degrees");
}

const score = 200;
if(score > 100){
    let power = "fly";
    console.log(`User power: ${power}`);
}

const balance = 1000;

if(balance > 500) console.log("test"), console.log("test 2")

    if(balance < 500){
        console.log("Less than 500");
    } else if(balance < 750){
        console.log("Less than 750");
    } else if(balance < 900){
        console.log("Less than 900");
    } else {
        console.log("Less than 1200");
    }

const userLoggedIn = true;
const debitCard = true;
const loggedInFromGoogle = false;
const loggedInFromEmail = true

if(userLoggedIn && debitCard && 2 == 3){
    console.log("Alow to buy courses");
}

if(loggedInFromEmail || loggedInFromGoogle){
    console.log("User is logged in");
}

switch

const month = "march";

switch (month) {
    case "jan":
        console.log("January");
        break;
    case "feb":
        console.log("February");
        break;
    case "march":
        console.log("March");
        break;
    case "april":
        console.log("April");
        break;

    default:
        console.log("Default case match");
        break;
}

Truthy

const userEmail = [];

if(userEmail){
    console.log("Got user email");
} else {
    console.log("No user email found")
}

// falsy values - 0, "", null, undefined, false, NaN, -0, BigInt

// truthy values
// "0", "false", " ", {},[], function({})

if(userEmail.length === 0){
    console.log("Array is empty");
}

const emptyObj = {};

if(Object.keys(emptyObj).length === 0){
    console.log("Object is empty");
}

// nullish coalescing (??): null undefined

let val1;
val1 = 5 ?? 10;
val1 = null ?? 10;
val1 = undefined ?? 13;
val1 = null ?? 10 ?? 15;
console.log(val1)

// ternary - condition ? true : false

const iceTeaPrice = 100;
iceTeaPrice <= 80 ? console.log("Less than 80") : console.log("More than 80");