/*

new ES features:JS advance topics

let const

default parameter for function

Arrow function

rest parameter

spread operator

for ..of

for ..in

string literals

Destructuring

modules

class and its ecosystem

symbol

generators and iterators

promise and async await

Map and Set, weakMap, weakSet

iterable objects

*/

//let const

// blocked scope

// we can access global variable using var keyword-- this is not recommended

// We can redeclare using var but we cant redeclare using let or const

// temporary dead zone

/*

a=10;

var a;

var a=10;

console.log(a);

console.log(globalThis.a)

let b=80;

b=90;

*/

//default parameter for function

/*

function sum(a,b=50){

return a+b;

}

console.log(sum(4,5));

*/

// arrow function

/*

let sum = (a, b) => a + b;

var name = "Ankur"

let obj = {

name: "bittu",

getName: function () {

return () => {

console.log(this);

return this.name;

}

}

}

console.log(obj.getName()());

*/

// rest parameter

/*

function rest(para1, para2, ...para3){

console.log(para1); // 3

console.log(para2); // 5

console.log(para3); // [7, 9, 11]

}

rest(3, 5, 7, 9, 11)

// spread operator

let arr1= [1,2,4,5,6,3];

rest(...arr1);

*/

// for -of and for-in

// for-of loop

/*

const arr = [1, 2, 3, 4, 5];

for (const element of arr) {

console.log(element);

}

// for-in loop

const obj = { a: 1, b: 2, c: 3 };

for (const key in obj) {

console.log(key, obj[key]);

}

*/

// string literals

/*

let a=10;

console.log(`value of a is ${a}`)

*/

// destrcuturing

let arr=[1,2,3,4];

let [a,b,c,d]= arr;

console.log(a);

console.log(b);

console.log(c);

let obj1={name:"bittu", age: 30};

let {name: name1, age} = obj1;

console.log(name1);

console.log(age);