DEV Community: Imran Hasan

What is Experss js

Imran Hasan — Mon, 27 Dec 2021 10:03:37 +0000

ExpressJS is a web application framework that provides us with a simple API to build websites, web apps and back ends. With ExpressJS, we need not worry about low level protocols, processes, etc. Fast, unopinionated, minimalist web framework for Node.js

Express.js is a Node.js web application server framework, designed for building single-page, multi-page, and hybrid web applications. It is the de facto standard

What is Mongoose?

Imran Hasan — Mon, 27 Dec 2021 10:02:25 +0000

Mongoose is an Object Document Mapper (ODM). This means that Mongoose allows us to define objects with a strongly-typed schema that is mapped to a MongoDB document.Mongoose is a way to make connections with mongodb databases. It provides mongodb validation and query in a very simple manner and it makes development fast.
Mongoose provides an incredible amount of functionality around creating and working with schemas. Mongoose currently contains eight SchemaTypes that a property is saved as when it is persisted to MongoDB. They are:
String
Number
Date
Buffer
Boolean
Mixed
ObjectId
Array

CRUD Operations

Imran Hasan — Mon, 27 Dec 2021 07:50:29 +0000

Crud operation means create,read,update,delete data from frontend to backend.Suppose in a web page every user should create a user account on that site its called create operation.User also saw about their information its a read operation.User maybe change their personal information it means update and user can delete his account from server its a delete operation.

React Hooks

Imran Hasan — Sun, 26 Dec 2021 16:06:49 +0000

Hooks are the new feature which is introduced in the React 16.8 version. It allows you to use state and other React features without writing a class. Hooks are the functions which "hook into" React state and lifecycle features from function components. It does not work inside classes.
Hooks are backward-compatible, which means it does not contain any breaking changes. Also, it does not replace your knowledge of React concepts.
When to use a Hooks
If we write a function component, and then we want to add some state to it, previously we do this by converting it to a class. But, now we can do it by using a Hook inside the existing function component.
Rules of Hooks

Only call Hooks at the top level Do not call Hooks inside loops, conditions, or nested functions. Hooks should always be used at the top level of the React functions. This rule ensures that Hooks are called in the same order each time a component renders.
Only call Hooks from React functions We cannot call Hooks from regular JavaScript functions. Instead, we can call Hooks from React function components. Hooks can also be called from custom Hooks.

What is JSX

Imran Hasan — Sun, 26 Dec 2021 15:55:49 +0000

Jsx means Javascript xml.JSX makes it easier to write and add HTML in React.JSX allows us to write HTML elements in JavaScript and place them in the DOM without any createElement() and appendChild() methods.JSX converts HTML tags into react elements.

Example with Jsx:
const myelement =

'hello world!'

;
ReactDOM.render(myelement, document.getElementById('root'));
Example without Jsx:
const myelement = React.createElement('h1', {}, 'hello world!');

ReactDOM.render(myelement, document.getElementById('root'));

PropTypes in React

Imran Hasan — Sun, 26 Dec 2021 15:18:31 +0000

Props and prop type are important mechanisms in react.props which means “properties” props usually send data from one component to another component in react.If components send wrong data it will show errors and bugs.We pass different type of props like string,number,array,function,objects.When props are passed to a React component, they are checked against the type definitions configured in the propTypes property. When an invalid value is passed for a prop, a warning is displayed on the JavaScript console.``