DEV Community: Sanat Kumar Mohanta

Week-4 Day-6

Sanat Kumar Mohanta — Sun, 26 Dec 2021 19:37:25 +0000

My target: Now I am looking for an internship to develop my skill and knowledge. Then after completing the internship I want to join a full-time job.
Where and how: (কোথায় বা কোন দেশে জব খুজতেছো ):
I am especially interested in the USA, India, UK, etc.
Expectation: I want a paid internship. Because I want to develop my skill through it which will also support me financially then I want to join the full-time job.
আমার কি কি জিনিস ইম্প্রুভ করা উচিত
Ans: I think I need to improve my skill specially on backend.I also want to learn MySQL though I worked on MongoDB.In addition, I want to develop my skills in new technologies also.I want to focus on redux, angular, MySQL, etc.
Sincerity: Time management
Ans :
Sincerity :
A sincere person takes pride in their work and is careful of the ramifications their actions can have on others. Sincerity is an essential element of life. A sincere person is always welcomed because of his truthful mind, friendly attitude, and unaffected and real personality.

Time management :
Time management affects performance and productivity at work. It will improve employee efficiency and help to meet deadlines, and produce better quality work. Improving your time management at work allows you to enhance your performance and achieve your desired goals.

Professionalism: The concept of professionalism goes beyond ethics; it encompasses image, manners, respect, appearance, excellence, quality, expertise, and other factors.
Honestly: We believe honesty is the foundation of deep and meaningful relationships between companies and their employees and customers.
Commitment: Job commitment is the feeling of responsibility that a person has towards the mission and goals of an organization. When an individual has job commitment, he or she is more likely to perform tasks and responsibilities that will help an organization achieve a goal.
Challenge
Challenging jobs provide an opportunity to strengthen, develop, and learn skills applicable to the work world. That’s why I like challenges in my job which make me so happy after success.
Ethics
Examples of ethical behaviors in the workplace include; obeying the company's rules, effective communication, taking responsibility, accountability, professionalism, trust, and mutual respect for your colleagues at work.

Week -4 Day -5 (Backend)

Sanat Kumar Mohanta — Sun, 26 Dec 2021 17:22:50 +0000

What are the four CRUD operations?

Ans: CRUD is an acronym that stands for Create, Read, Update, and Delete. These are the four most basic operations that can be performed with most traditional database systems and they are the backbone for interacting with any database.

Mongoose :

Mongoose is an Object Data Modeling (ODM) library for MongoDB and Node.js. It manages relationships between data, provides schema validation, and is used to translate between objects in code and the representation of those objects in MongoDB.

Relational database (MySql) :

Is MySQL a database or DBMS?
MySQL is a relational database management system (RDBMS) developed by Oracle that is based on structured query language (SQL). A database is a structured collection of data. It may be anything from a simple shopping list to a picture gallery or a place to hold the vast amounts of information in a corporate network.

Express: Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.

Express.js, or simply Express, is a back-end web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs. It has been called the de facto standard server framework for Node.js.

What is JSON Web Token?

JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed. JWTs can be signed using a secret (with the HMAC algorithm) or a public/private key pair using RSA or ECDSA.
Although JWTs can be encrypted to also provide secrecy between parties, we will focus on signed tokens. Signed tokens can verify the integrity of the claims contained within it, while encrypted tokens hide those claims from other parties. When tokens are signed using public/private key pairs, the signature also certifies that only the party holding the private key is the one that signed it.

When should you use JSON Web Tokens?

Here are some scenarios where JSON Web Tokens are useful:
Authorization: This is the most common scenario for using JWT. Once the user is logged in, each subsequent request will include the JWT, allowing the user to access routes, services, and resources that are permitted with that token. Single Sign-On is a feature that widely uses JWT nowadays, because of its small overhead and its ability to be easily used across different domains.
Information Exchange: JSON Web Tokens are a good way of securely transmitting information between parties. Because JWTs can be signed—for example, using public/private key pairs—you can be sure the senders are who they say they are. Additionally, as the signature is calculated using the header and the payload, you can also verify that the content hasn't been tampered with.

JavaScript Week-4 Day-4

Sanat Kumar Mohanta — Sun, 26 Dec 2021 15:11:05 +0000

context API: The Context API is a React structure that enables you to exchange unique details and assists in solving prop-drilling from all levels of your application.

JSX : JSX stands for JavaScript XML. It is simply a syntax extension of JavaScript. It allows us to directly write HTML in React (within JavaScript code)

HOOKS: Hooks are JavaScript functions, but they impose two additional rules:

Only call Hooks at the top level. Don't call Hooks inside loops, conditions, or nested functions.
Only call Hooks from React function components. Don't call Hooks from regular JavaScript functions.

custom hooks: Custom Hook is a JavaScript function which we create by ourselves when we want to share logic between other JavaScript functions. It allows you to reuse some piece of code in several parts of your app.

State-props: Props are used to pass data, whereas state is for managing data. Data from props is read-only, and cannot be modified by a component that is receiving it from outside. State data can be modified by its own component.

What is the use of PropTypes?

PropTypes are a mechanism to ensure that components use the correct data type and pass the right data, and that components use the right type of props, and that receiving components receive the right type of props.

Performance Optimization Techniques for React Apps

Using Immutable Data Structures.
Function/Stateless Components and React.
Multiple Chunk Files.
Use React.
Avoid Inline Function Definition in the Render Function.
Throttling and Debouncing Event Action in JavaScript.
Avoid using Index as Key for map.

Scope: Scope determines the accessibility of variables to JavaScript. The two types of scope are local and global:

Global variables are those declared outside of a block

Local variables are those declared insides of a block

What is hoisting in JavaScript?

In JavaScript, Hoisting is the default behavior of moving all the declarations at the top of the scope before code execution.

JavaScript Basics

Sanat Kumar Mohanta — Sun, 26 Dec 2021 10:12:16 +0000

Truthy and Falsy values in javascript :

In javascript falsy values are defined as :

when the condition is false 2.when value = 0
empty string is also a falsy value
Null is a falsy value
Undefined is also falsy
NaN is also falsy

In javascript truthy values are defined as:

When the condition is true
Any numbers (negative or positive)
Any string including single white space 4.[] an empty array
{} an empty object
anything that is not falsy will be truthy
```
              **Null vs undefined** 
```

undefined

:
It means a variable is declared, but no value has been assigned a value.
For example,
var demo;
alert(demo); //shows undefined
alert(typeof demo); //shows undefined

null :

Whereas, null in JavaScript is an assignment value. You can assign it to a variable.
For example,
var demo = null;
alert(demo); //shows null
alert(typeof demo); //shows object

double equal (==) vs triple equal (===) in javascript

== in JavaScript is used for comparing two variables, but it ignores the datatype of the variable. === is used for comparing two variables, but this operator also checks datatype and compares two values.