1.Null vs Undefined.

Null is a special value meaning “no value”. null is a special object because type of null returns ‘object’.
On the other hand, undefined means that the variable has not been declared, or has not been given a value.


Null means an empty or non-existent value. Null is assigned, and explicitly means nothing.

// null
var test-1 = null;
// object
console.log(type of test1);


Undefined means a variable has been declared, but the value of that variable has not yet…

1.React & its history

React is an open-source, front end, JavaScript library for building user interfaces or UI components. It is maintained by Facebook and a community of individual developers and companies. React can be used as a base in the development of single-page or mobile applications.

It was first deployed on Facebook’s News Feed in 2011 and later on Instagram in 2012. It was open-sourced at JSConf US in May 2013. React Native, which enables native Android, iOS, and UWP development with React, was announced at Facebook’s React Conf in February 2015 and open-sourced in March 2015.

2.Features of…

1.Error Handling

Errors is a part of code so it appears every times in code. So all the time we need to handle errors. there are some keywords for error handling in JavaScript.


  1. catch statements let you handle those error.
  2. the through statements let you create customer errors.
  3. and the finally statement let you execute after trying catch regardless of the result.
try {
// code…
catch (error) {
// error handling


1. Introduction to JavaScript

Java Script is a simple, powerful language (scripting/programming) language that allows to implementation of complex features on web pages. It is a multi-paradigm, dynamic language with types and operators, standard built-in objects, and methods. Its syntax is based on the Java and C languages. it help us to make our web pages functional. So we call Java Script the heart of the web.

JavaScript supports object-oriented programming with object prototypes, instead of classes. it also supports functional programming, functions may be stored in variables and passed around like any other object.

There are three main…

Md. Nur-E-Alom Siddiky

A progressive JavaScript Developer and part time writer.

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