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1. Null vs Undefined:

In Javascript null is assigned value, which means this value doesn't exist. Without assigning a value of null, you can not get from anywhere by Javascript a Null result.

var assign = null;console.log(assign); //==>  null

‘Null’ result can get only by assigning a variable with ‘null ’ value, which is shown in the example. Javascript Programmer uses this value for different purposes.

In JavaScript Undefined means previously a variable is declared by a programmer but he/she never assigned any value there. We can get Undefined results in many cases.

var taka;
console.log(taka) //==> undifined

There's several ways you can get undefined;

var object = { name…

What is React?

React is a front-end JavaScript library developed by Facebook in 2011. It follows the component-based approach which helps in building reusable UI components. It is used for developing complex and interactive web and mobile UI. Even though it was open-sourced only in 2015, it has one of the largest communities supporting it.

Let's talk about some basic concepts of react.


JSX is a syntax extension to JavaScript. It is used with React to describe what the user interface should look like. By using JSX, we can write HTML structures in the same file that contains JavaScript code.


The smallest and…

1. Try …Catch:

During javascript code execution there are errors that might occur results blocked the whole execution. Sometimes programmers face a great problem dealing with these hidden errors.

Errors can be occurred due to giving in wrong input, applying the wrong syntax, and other unforeseeable things.

We can easily handle these issues by applying the try-catch method.

// code start to execute the whole code, unless it'll find any error
//if any error found in try , then catch is began to execute and execution doesnt blocked due to error. …

String Methods:

1. charAt():

charAt() indicates the specific character according to the given parameter, index number.

var color = "red";//console.log
color.charAt(0) = "r"
color.charAt(2) = "d"
//Note that index should be>> string.length-1

2. concat():

concat function adds or combines two or more types of string. Simply says Concat act as a jointer or glue here!

var subject = "She"
var predicate = "loves me"
concate(subject, predicate)
//result will be "She loves me"

3. includes():

It gives you a boolean result comparing two or string under a condition. An example helps you to get that concept more clearly,

const jhonySaid = "Sunny…

Uniform Resource Locator shortly is URL called the global address of documents and World Wide Web.

For instance, if you look at the example which is given below, you will see:

— This is the URL of the web page you are viewing right now.

The URL Syntax

The general syntax of URLs is the following:

Scheme name —

The very first part of the URL is a scheme. Also known as “protocol” identifies the protocol to be used to access the resource over the internet.

The most commonly used protocols are HTTP://, HTTPS://, ftp://, and mailto://.

Hostname —

A hostname is nothing but…

Ridwanul Alam

A Frontend Web Developer. Devoted to solving new problems and developing interactive web application

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