//use of var keyword-> variable scope globally
console.log(name);
var name="lalit";
name="abc";
console.log(name);
name="test";
console.log(name);
//use of let keyword-> variable scope within the block
//console.log(name);
let name="lalit";
name="abc";
console.log(name);
name="test";
console.log(name);
//use of const keyword-> variable can not possible reassign
//console.log(name);
const name="lalit";
console.log(name);
name="test";
console.log(name);
*********************************************
//Function Declaration ES5
function greet(name) {
return "Hello" + " " + name;
}
console.log(greet("lalit"));
//Function Declaration ES6 (Arrow Function)
const greet= (name) => {
return "Hello There" + " " + name;
};
console.log(greet("Lalit"));
or
const greet= name => { //put code here };
//Function Declaration Multiple Parameter ES6 (Arrow Function)
const greet= (name,age) => {
return "Hello There" + " " + name + " " + age;
};
console.log(greet("Lalit",30));
//Function Declaration Single Parameter ES6 (Arrow Function)
const Sqr = num => {
return num*num;
};
console.log(Sqr(6));
or write this
const Sqr = num => num*num;
console.log(Sqr(6));
*******************************
//this Keyword with Arrow Function
//ES5
const person = {
test(){
console.log(this);
},
};
person.test();
--------------------------------------------------------------------------
const person = {
test(){
var self = this;
setTimeout( function(){
console.log(self);
}, 2000);
},
};
person.test();
ES6
const person = {
test(){
//var self = this;
setTimeout(() => {
console.log(this);
}, 2000);
},
};
person.test();
*******************************
//Template Literals
-ES5
var name = "lalit";
console.log("welcome to" + " " + name + " ! Have a nice day");
-ES6 -> use tiled symbol and ${varname}
const name1 = "lalit";
console.log(`welcome to ${name1} ! Have a nice day`);
//Print Multiline string in JS
-ES5
//var name = "lalit";
//var res = "Welcome \n to "+name;
//console.log(res);
-ES6
const name = "lalit";
const res = `welcome to Blue
world mandhana
${name}`;
console.log(res);
*************************************************
Objects Destructing in
-ES5
var details = {
name: "lalit",
contact: "1238899",
email: "abc@gmail.com"
}
var name = details.name;
var contact = details.contact;
var email = details.email;
console.log(name);
console.log(contact);
console.log(email);
-ES6
let detailsNew = {
name1: "lalit",
contact1: "1238899",
email1: "abc@gmail.com"
}
const {name1:company_name,contact1,email1} = detailsNew;
console.log(company_name);
console.log(contact);
console.log(email);
************************************
//Array Destructing in
-ES5
var arr = ["A1","A2","A3","A4"]
var v1 = arr[0];
var v2 = arr[1];
var v3 = arr[2];
var v4 = arr[3];
console.log(v1);
console.log(v2);
console.log(v3);
console.log(v4);
-ES6
var arres6 = ["B1","B2","B3","B4"];
let [var1,var2,var3,var4] = arres6;
console.log(var1);
console.log(var2);
console.log(var3);
console.log(var4);
************************************
Spread Operator
//const oldArray = [1,2,3,4,5];
//const newArray = ["A","B","C",...oldArray,6,7,8,9,10];
//console.log(newArray);
Rest Operator with limited same as parameter value
const sum = (a,b,c,d) => a+b+c+d;
console.log(sum(1,2,3,4));
//console.log(sum(1,2,3,4,5,6,7)); not handle more than parameter(4) value
Rest operator with infinite value
const sum = (...numbers) => {
let total = 0;
numbers.forEach((n) => {
total += n;
});
console.log(total);
}
sum(1,2,3,4,5,6,7,8)
************************************
//Array Map Method
const courses = ["PHP", "ReactJS", "AngularJS", "JavaScript"];
const newCourses = courses.map((c) => {
return `<li> ${c} </li>`;
});
console.log(courses);
console.log(newCourses);
--------------------------
const series = [1,2,3,4,5,6,7,8,9,10];
const num = 5;
const table = series.map((s) => s*num );
console.log(table);
************************************
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