DEV Community: Mahir-Ahsef

Express.js

Mahir-Ahsef — Thu, 23 Dec 2021 14:10:10 +0000

What is Express.js?

Express is a fast, aggressive, required, and minimal Node.js web framework. You can think about express as a layer that sits on top of Node.js and helps with server and route management. It includes a full set of tools for developing web and mobile applications.

Let's have a look at some of the most important aspects of the Express framework:

Single-page, multi-page, and hybrid web apps may all be created using it.
1. It enables middlewares to reply to HTTP requests to be configured.
2. It creates a routing table that is used to do various tasks 4. based on the HTTP method and URL.
3. It allows you to dynamically render HTML pages by providing variables to templates.

Aggregation

Mahir-Ahsef — Thu, 23 Dec 2021 13:46:17 +0000

Aggregation is the process of combining many things into a single meaningful entity. Aggregation develops a link between various entities in order to form a single entity. Because it allows the system to work properly, the final entity makes sense.

What is MySQL and its advantages?

Mahir-Ahsef — Thu, 23 Dec 2021 13:37:32 +0000

MySQL is at the top of the list of reliable transactional database engines on the market. It is the go-to solution for comprehensive data integrity, with capabilities including fully atomic, consistent, isolated, persistent transaction support, multi-version transaction support, and unlimited row-level locking.

Is Mongoose better than MongoDB?

Mahir-Ahsef — Thu, 23 Dec 2021 13:27:22 +0000

A user may specify the schema for the documents in a collection using mongoose. It makes the process of creating and managing data in MongoDB a lot easier. On the flip side, learning mongoose takes time and has certain limits when dealing with complicated schemas.

JWT (JSON Web Token)

Mahir-Ahsef — Thu, 23 Dec 2021 13:26:45 +0000

JWT (JSON Web Token) is an open standard that allows two parties — a client and a server to communicate security information. JSON items, containing a set of claims, are encoded in each JWT. JWTs are signed with a cryptographic technique to ensure that the claims can't be changed after they've been distributed.

CRUD Operations

Mahir-Ahsef — Thu, 23 Dec 2021 13:14:28 +0000

Answer: CRUD operations are the mix of Create, Read, Update and Delete.

Create: The Create operation is used to populate the MongoDB database with new documents.

There is two way to create documentations in a collections:
db.Userscollection.insertOne()
db.Userscollection.insertMany()

Read: The read operation is used to query a database document.

There is two way to read documentations in a collections:
db.Userscollection.findOne()
db.Userscollections.find()

Update: The Update operation is used to make changes to existing database documents.

To update documents in a collection, MongoDB supports the following methods:
db.Userscollection.updateOne()
db.Userscollection.updateMany()
db.Userscollection.replaceOne()
Delete: To delete documents from the database, utilize the Delete operation.

To delete documents from a collection, MongoDB supports the following methods:
db.Userscollection.deleteOne()
db.Userscollection.deleteMany()

diffing- algorithm

Mahir-Ahsef — Wed, 22 Dec 2021 15:06:32 +0000

The set of differences between two inputs is output by a diff algorithm. A number of widely used developer tools are based on these algorithms. A developer can view, commit, pull, and merge diffs without ever learning the underlying diff process in Git, for example.

Virtual DOM

Mahir-Ahsef — Wed, 22 Dec 2021 15:02:40 +0000

The virtual DOM (VDOM) is a programming concept in which a library, such as ReactDOM, stores a "virtual" representation of a user interface in memory and syncs it with the "real" DOM. Reconciliation is the term for this. They might also be thought of as a part of React's "virtual DOM" implementation.

context API in reactjs

Mahir-Ahsef — Wed, 22 Dec 2021 14:58:19 +0000

When numerous components at various nesting levels need access to the same data, context is employed. It should be used with caution because it makes component reuse more difficult. Component composition is typically a simpler approach than context if you merely want to avoid providing some props over several layers.

Hooks in reactJS

Mahir-Ahsef — Wed, 22 Dec 2021 14:54:23 +0000

Hooks make it possible to use React's state and other features without needing to create a class. Hooks are state and lifecycle aspects in React that function components "hook onto." It is ineffective in a school context. Hooks are backward-compatible, meaning they don't add any new functionality. It also doesn't substitute for your knowledge of React concepts.

When Should You Use Hooks?

If you create a function component and later wish to add any state to it, you must first convert it to a class. However, you can now do so by incorporating a Hook into an existing function component.

Hooking Rules

Hooks are identical to JavaScript functions, but while utilizing them, you must obey these two rules. The hooks rule ensures that all of a component's stateful logic is visible in its source code. These are the rules:

1. Only use Hooks at the highest level.

Hooks aren't supposed to be called from loops, conditions, or nested functions. At all times, hooks should be utilized at the top level of React methods. When a component renders, this rule ensures that Hooks are called in the same order each time.

2. Hooks should only be called from React functions.

Hooks can't be called from JavaScript functions. Hooks can be called from React function components instead. Custom Hooks can also be used to call Hooks.

custom Hooks in React

Custom Hooks are a way to reuse stateful logic (such as setting up a subscription and remembering the current value), but each time you use one, all states and effects within it are completely isolated. What causes a custom Hook to become isolated? Each Hook call is given its own state.

Component Lifecycle in reactJS

Mahir-Ahsef — Wed, 22 Dec 2021 14:21:09 +0000

Components are generated (mounted on the DOM), updated, and subsequently decommissioned (unmount on DOM). A component lifespan is a term used to describe this process. At different stages of a component's life, React provides multiple lifecycle methods.... We understand what lifecycle methods are and why they are crucial at this time.

JSX in reactJS

Mahir-Ahsef — Wed, 22 Dec 2021 14:16:34 +0000

JavaScript XML is abbreviated as JSX. It's just a JavaScript syntax extension. It allows us to write HTML directly in React (within JavaScript code). It is straightforward to generate a template in React using JSX, but it is not a simple template language; instead, it contains all of JavaScript's capability.