 // function calcTime(city, offset) {

//     // create Date object for current location
//     var d = new Date();
   
//     // get UTC time in msec
//     var utc = d.getTime();
   
//     // create new Date object for different city
//     // using supplied offset
//     var nd = new Date(utc + (3600000*offset));
   
//     // return time as a string
//     return "The local time in " + city + " is " + nd.toLocaleString();
// }
// var x=calcTime("Canada",);
// console.log(x)


// function changeTimezone() {
      
//             let date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));
                       
              
//             console.log('Given IST datetime: ' + date);
          
//             let intlDateObj = new Intl.DateTimeFormat('en-US', {
//                 timeZone: "America/New_York"
//             });
          
//             let usaTime = intlDateObj.format(date);
//             console.log('USA date: ' + usaTime);
//         }
        
//         changeTimezone()

// function a(datetime,exp_tz) {
// var date = new Date(datetime);
// var localTime = date.getTime();
// var a=exp_tz;


// // get local timezone offset and convert to milliseconds
// var localOffset = date.getTimezoneOffset() * 60000;

// // obtain the UTC time in milliseconds
// var utc = localTime + localOffset;

// if(a=="GMT"){

// let newDateTime = utc + (3600000 * -5.5);

// let convertedDateTime = new Date(newDateTime);
// return convertedDateTime.toLocaleString();
// }
// else if(a=="IST"){
// newDateTime = utc + (3600000 * 1);

// let convertedDateTime = new Date(newDateTime);
// return convertedDateTime.toLocaleString();
// }
// else if(a=="PST"){

// newDateTime = utc + (3600000 * -0.5);

// let convertedDateTime = new Date(newDateTime);
// return convertedDateTime.toLocaleString();
// }
// else{
// let convertedDateTime = new Date(newDateTime);
// return convertedDateTime.toLocaleString();
// }
// }

// var x=a();
// console.log(x)


// const date1 = new Date('August 19, 1975 23:15:30 GMT+07:00');
// const date2 = new Date('August 19, 1975 23:15:30 GMT-02:00');

// console.log(date1.getTimezoneOffset());
// // expected output: your local timezone offset in minutes
// // (eg -120). NOT the timezone offset of the date object.

// console.log(date1.getTimezoneOffset() === date2.getTimezoneOffset());
// // expected output: true


// function changeTimezone() {
     
//     let date = new Date(Date.UTC(2021, 5, 28, 3, 0, 0));
//     console.log('Date in India: ' + date);
//     let formatter = new Intl.DateTimeFormat('en-US', { timeZone: "America/Denver" });   
//     let usDate = formatter.format(date);
//     console.log('Date in USA: ' + usDate);
// }

// changeTimezone()


// function a(datetime,exp_tz) {
// var date = new Date(datetime);
// var localTime = date.getTime();
// var a=exp_tz;
// // get local timezone offset and convert to milliseconds
// var localOffset = date.getTimezoneOffset() * 60000;
// // obtain the UTC time in milliseconds
// var utc = localTime + localOffset;
// if(a=="GMT"){
// var newDateTime = utc + (3600000 * -5.5);
// var convertedDateTime = new Date(newDateTime);
// return convertedDateTime.toLocaleString();
// }
// else if(a=="IST"){
// var newDateTime = utc + (3600000 * 1);
// var convertedDateTime = new Date(newDateTime);
// return convertedDateTime.toLocaleString();
// }
// else if(a=="PST"){
// var newDateTime = utc + (3600000 * -0.5);
// var convertedDateTime = new Date(newDateTime);
// return convertedDateTime.toLocaleString();
// }
// else{
// var convertedDateTime = new Date(newDateTime);
// return convertedDateTime.toLocaleString();
// }
// }

// var x=a();
// console.log(x)



// const a=10;

// console.log(a);

// const o={"name":"abc","age":28};
// // console.log(o)

// // console.log(o.name)
// o.age=30;

// console.log(o.age)






// const date = new Date();

// let day = date.getDate();
// let month = date.getMonth() + 1;
// let year = date.getFullYear();

// let currentDate = `${month}/${day}/${year}`;
// console.log(currentDate); // "17-6-2022"
// var date1 = new Date();

// function t(Invoice_Generation_Date) {
    
//     // var date1 = new Date(Invoice_Generation_Date);
// var  diffDays = ((date1.getMonth()+1)+"/"+date1.getDate()+"/"+date1.getFullYear()+" "+date1.getHours()+":"+date1.getMinutes()+":"+date1.getSeconds());
// return diffDays;
// }
// var t1=t();
// console.log(t1)

// var m1 = new Date('21-11-2022');
// var m2 = new Date('22-11-2022');
// var m3 = m2(m1,'minutes');
// var m4 = m2(m1,'h');
// var numdays = Math.floor(m3 / 1440);
// var numhours = Math.floor((m3 % 1440) / 60);
// var numminutes = Math.floor((m3 % 1440) % 60);
// console.log(numdays + " day(s) " + numhours +"h " + numminutes +"m");

// function dateDiff( str1, str2 ) {
//     var diff = Date.parse( str2 ) - Date.parse( str1 ); 
//     return isNaN( diff ) ? NaN : {
//         diff : diff,
//         ms : Math.floor( diff            % 1000 ),
//         s  : Math.floor( diff /     1000 %   60 ),
//         m  : Math.floor( diff /    60000 %   60 ),
//         h  : Math.floor( diff /  3600000 %   24 ),
//         d  : Math.floor( diff / 86400000        )
//     };
// }
// var r=dateDiff('21-11-2022','23-11-2022');
// console.log(r);


// var a=new Date();
// console.log(a);

// function t(s1,s2)
// {

//   // var diff =(s2.getTime() -s1.getTime()) / 1000;
//     var diff =(s2 -s1) / 1000;

//   diff /= 60;
//   return Math.floor(diff)+" Minutes";
  
// }
// var t1=t('21-11-2022   ','23-11-2022');
// console.log(t1)
 
 
//   function(s1,s2)
// {

//   var diff =((Current_Date_Exp.getTime()) - (Invoice_Generation_Date.getTime())) / 1000;
//   diff /= 60;
//   return Math.floor(diff)+" Minutes";
  
// }

// function diff_minutes(dt2, dt1) 
// {

//   var diff =(dt2.getTime() - dt1.getTime()) / 1000;
//   diff /= 60;
//   // return Math.abs(Math.round(diff))+" Minutes";
//     return Math.abs(diff)+" Minutes";

  
// }

// dt1 = new Date(2022,10,2);
// dt2 = new Date(2022,10,3);
// console.log(diff_minutes(dt1, dt2));

created 2 years ago

Javascript Online Compiler

Write, Run & Share Javascript code online using OneCompiler's JS online compiler for free. It's one of the robust, feature-rich online compilers for Javascript language. Getting started with the OneCompiler's Javascript editor is easy and fast. The editor shows sample boilerplate code when you choose language as Javascript and start coding.

About Javascript

Javascript(JS) is a object-oriented programming language which adhere to ECMA Script Standards. Javascript is required to design the behaviour of the web pages.

Key Features

Open-source
Just-in-time compiled language
Embedded along with HTML and makes web pages alive
Originally named as LiveScript.
Executable in both browser and server which has Javascript engines like V8(chrome), SpiderMonkey(Firefox) etc.

Syntax help

STDIN Example

var readline = require('readline');
var rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
  terminal: false
});

rl.on('line', function(line){
    console.log("Hello, " + line);
});

variable declaration

Keyword	Description	Scope
var	Var is used to declare variables(old way of declaring variables)	Function or global scope
let	let is also used to declare variables(new way)	Global or block Scope
const	const is used to declare const values. Once the value is assigned, it can not be modified	Global or block Scope

Backtick Strings

Interpolation

let greetings = `Hello ${name}`

Multi line Strings

const msg = `
hello
world!
`

Arrays

An array is a collection of items or values.

Syntax:

let arrayName = [value1, value2,..etc];
// or
let arrayName = new Array("value1","value2",..etc);

Example:

let mobiles = ["iPhone", "Samsung", "Pixel"];

// accessing an array
console.log(mobiles[0]);

// changing an array element
mobiles[3] = "Nokia";

Arrow functions

Arrow Functions helps developers to write code in concise way, it’s introduced in ES6.
Arrow functions can be written in multiple ways. Below are couple of ways to use arrow function but it can be written in many other ways as well.

Syntax:

() => expression

Example:

const numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
const squaresOfEvenNumbers = numbers.filter(ele => ele % 2 == 0)
                                    .map(ele => ele ** 2);
console.log(squaresOfEvenNumbers);

De-structuring

Arrays

let [firstName, lastName] = ['Foo', 'Bar']

Objects

let {firstName, lastName} = {
  firstName: 'Foo',
  lastName: 'Bar'
}

rest(...) operator

 const {
    title,
    firstName,
    lastName,
    ...rest
  } = record;

Spread(...) operator

//Object spread
const post = {
  ...options,
  type: "new"
}
//array spread
const users = [
  ...adminUsers,
  ...normalUsers
]

Functions

function greetings({ name = 'Foo' } = {}) { //Defaulting name to Foo
  console.log(`Hello ${name}!`);
}
 
greet() // Hello Foo
greet({ name: 'Bar' }) // Hi Bar

Loops

1. If:

IF is used to execute a block of code based on a condition.

Syntax

if(condition){
    // code
}

2. If-Else:

Else part is used to execute the block of code when the condition fails.

Syntax

if(condition){
    // code
} else {
    // code
}

3. Switch:

Switch is used to replace nested If-Else statements.

Syntax

switch(condition){
    case 'value1' :
        //code
        [break;]
    case 'value2' :
        //code
        [break;]
    .......
    default :
        //code
        [break;]
}

4. For

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
//code  
}

5. While

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
  // code 
}

6. Do-While

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
  // code 
} while (condition);

Classes

ES6 introduced classes along with OOPS concepts in JS. Class is similar to a function which you can think like kind of template which will get called when ever you initialize class.

Syntax:

class className {
  constructor() { ... } //Mandatory Class method
  method1() { ... }
  method2() { ... }
  ...
}

Example:

class Mobile {
  constructor(model) {
    this.name = model;
  }
}

mbl = new Mobile("iPhone");