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/**
 * Literals and Variable declaration
 * Arrow Function
 * ES6 Classes , Object destrucing
 * Async Programing - Classbacks, Promises
 * Modularity - Es6 Modules
 */

/**
 * How to declare variable
 * 1.var => ES%
 * 2. let and const => ES6
 * var variablename = value(literals)
 * // number,string,boolean,undefined,infinity,NAN,function,null,object
*/

let city = 'Chennai';
console.log("Name:" + city)
console.log(`City: ${city}`)
console.log(
    `
    helloo
    hi
    sample
    here
    `
)
/**let htmlDoc = "<html>" +
    "<body>" +
    "<h1>" +
    "Hello" +
    "</h1>" +
    "</body></html>"*/

 //multiline: es 6
let htmlDocEs6 = `<html>
    <body>
    <h1>
    Hello
    </h1>
    </body>
    </html>
    `
console.log(htmlDocEs6)

let price = 100;
console.log(`Price Given : ${price}`);

let isActive = true;
console.log(`Status Given : ${isActive}`);

let qty;
console.log(`Quantity : ${qty}`);

let totalprice = price*qty;
console.log(`Total Price : ${totalprice}`)

let gst = "10";
let totalInvoice = parseFloat(gst) * 8/100;
console.log(`Print Invoice : ${totalInvoice}`);

/**
 * 1.boolean Flase
 * "", '' (Empty String)
 * undefined
 * 0
 * null
 * NAN
 */

if(isActive){
    console.log("Status is Active")
}else{
    console.log("Status is not Active")
}

let name = "ram";
if(name){
    console.log("person is present");
}else{
    console.log("person is not present");
}

// Mostly in react constants are used

const pi = 3.14;
console.log(`PI : ${pi}`);
//pi = 30;

/**
 * Function
 *
 */

function add(){
    console.log("this is a function to add");
}

// Invoke Function
add()
// a, b are arg
// default args
function add_something(a=1,b=2){
    const result = a+b;
    console.log(result);
}
//5, 6 are parameter , any literals can be passed
add_something(5,6);
add_something(5);
add_something();
add_something("sample", "hi")

function logger(screen,...args){
    console.log(screen, args);
}
//req for logger : Paramter Dynamic
logger("dashboard", "hi");
logger("Home", "hi", "hello")

//return types

function do_login(username, password){
    /* if(username === "admin" && password === "admin"){
        return true;
    }
    return; */
    return (username === "admin" && password === "admin") ? true : false
}

do_login('admin', 'admin') ? console.log('Valid User') : console.log('Unauthenticated User');

/**
 * Arrow Functions
 *  -> can assign function to variable
 *  -> can be returned from another function
 *  -> can be passed as parameter to another function
 */

// How to assign a function to a variable
//var/let/const
/**
 * Function can be assigned to var
 * that var can be used to an function
 */

const add = function(a,b){
    console.log(a+b);
    return a+b;
}
var sample = add(1212,6);

console.log(sample)

/**
 * Arrow Function
 */

let do_multiply = (a,b) =>{
    console.log(a*b);
}

do_multiply(5,6)

//if function has no body , only one line , we can remove {}

const do_division = (a,b) => {return a/b};
console.log(do_division(100,5))