JavaScript has some tricky concept which is turned to be most important when you are preparing yourself for an interview.

Truthy vs Falsy

This is one of the JavaScript tricky concepts. A value that is always equal to a boolean value called “True” is truthy . On the other hand, a value which is always equal to a boolean value called “False” is falsy . Let me give you some example bellow:

Truthy Value

  1. A string holding a zero like: (‘ 0 ’)
  2. White space given in empty string.
  3. A string holing a text like: (‘ false ’)
  4. An empty array like: []

Are you a React JS lover? Do you want to know about React JS ? Then you are in the right place now. Here you will learn about the core concepts of React JS. So welcome here and enjoy learning.

What is React?

Definitely, the first question that will go on your mind is this. React is an effective, and flexible JavaScript library for building user interfaces. It is a tool for building UI components. It’s not a framework, but it’s a magical solution for Facebook to handle billions of posts, millions like count, millions of comments without reloading for the web page.

Why React?

Data Types

Data types specify what kind of data can be stored and manipulated within a program.In JavaScript, there are six basic data types which can be divided into three main categories:

1. Primitive

2. Composite

3. Special

String, Number, and Boolean are primitive data types. Object, Array, and Function are composite data types. Whereas Undefined and Null are special data types.

JavaScript is an open and cross-platform scripting or programming language that allows you to implement complex features on web pages. JavaScript is easy to implement because it is combined with HTML.


First of all, the number is a primitive data type in JavaScript. Number type represents integer, float, hexadecimal, octal value. The Number type introduces some default properties. Since JavaScript uses primitive values as an object, so all the properties and methods apply to both primitive number values and number objects. We can convert a string to an integer using a built-in function called parseInt(). …

Ahmed Reza Shah

Front End Developer | MERN Stack Developer | JavaScript & React Enthusiast | Network Engineer

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store