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Some javascript theory we need to know, helpful before an interview.

Img by adeolu from unsplash


Truthy and Falsy values, Null vs Undefined, double(==) vs Tripe(===), scopes, closure, encapsulation, private variable.

Bind, call and apply, window and global variable, new and this keyword, JS asynchronous.

Some problem-solving technics.

Truthy and Falsy values:

Truthy means true value and falsy means false value.
In JavaScript, a truthy value is a value that is considered true when encountered in a Boolean context. All values are truthy unless they are defined as falsy.

Examples of truthy values in JavaScript:

if (true){console.log("Truthy Value")} 
if ({}){console.log("Truthy Value")}
if ([]){console.log("Truthy Value")}
if (42){console.log("Truthy Value")}
if ("0"){console.log("Truthy Value")}
if ("false"){console.log("Truthy Value")}

React Core concept, Virtual Dom and Diff algorithm, JSX, Default Props, Prop Types, Optimizing performance, Some essentials about react.

By ferenc from unplash

React Core Concept:

React is defined as a JavaScript library for building user interfaces. Let’s start by talking about the two different parts of this definition.

Data Types, Error handling, Coding Style, Caching, Cross Browser, Hoisting, Block level, Default parameter, Spread operator, Arrow function

By tracy from unspalsh

Data Types in Javascript

What are data types? Data types specify what kind of data can be stored or manipulated within a program.

The latest ECMAScript standard defines nine types.

In a short, there are mainly six basic data types in Javascript, which we can divide into three main categories: 1. primitive(or primary) 2. composite(or reference), and 3. special data types.

Primitive data types:

String, Number, and Boolean are primitive data types.

Composite data types:

Object, Array, and Function are composite data types.

Special data types:

Undefined and Null are special data types.


An expression…

String, Number, and Array

Photo by Ferenc from Unsplash
Photo by Ferenc from Unsplash
<h2>My First JavaScript</h2>
<button type="button"
onclick="document.getElementById('demo').innerHTML = 'Hello Reader'">
Click me to display Date and Time.</button>
<p id="demo"></p>

JavaScript is a lightweight, interpreted, or just-in-time compiled programming language.
One of the most popular programming languages for web development.
It was mainly used for the front-end only. Nowadays backend development is super easy by using Node.
Anyway, we have to learn the basics of Javascript. Let's go for String, Number, and Array.

String :

JavaScript strings are used for storing and manipulating text. a string is zero or more characters written inside single or double-quotes.

Example :

var x = "Khalid…

Test2 story

I am testing medium platform to share my story.

Teaching Method

Mahfuz Khalid

Nothing to say more at this moment.

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