main README

Review to ES6 Classes :

what is classes : Classes are a template for creating objects, Classes are in fact “special functions”.

how we use class in our code ?

• we need to define it by :
• using a class declaration,we can declarate class by using the class keyword with the name of the class

example :

class car {
  constructor(Type, color , price) {
    this.Type = Type;
    this.color = color;
    this.price = price;
  }
}

• another way to define a class is A class expression , Class expressions can be named or unnamed. The name given to a named class expression is local to the class’s body.
• it can be accessed via the name property.

hoisting in classes :

is different from functions hoisting in functions we can call it any where any time , but when using classes you have to declarate if berfor calling it .

Class body and method definitions :

-Strict mode -Constructor -Static initialization blocks -Prototype methods -Generator methods -Static methods and properties

Express Routing :

Routing refers to how an application endpoint (URI) respond to client requests

Example: app.get(‘/’, (req, res) => { res.send(‘welcome’) })

in this example : a get request send to by client to the server on path “/” which is the home page and the client will recive a respones massage “welcome”

and we have dirrerent type of request we can send it to the sever , like : -GET -POST -DELETE -PUT and each and every one of these methods we serponse on deferent way from the other :

GET request will Get data delete request will delete data post request will insert data put request will update data

and we have dirrerent type of response we can send it to the client , like :

-res.download(): Prompt a file to be downloaded. -res.end(): End the response process. -res.json(): Send a JSON response. -res.jsonp(): Send a JSON response with JSONP support. -res.redirect() :Redirect a request. -res.render(): Render a view template. -res.send() :Send a response of various types. -res.sendFile(): Send a file as an octet stream. -res.sendStatus(): Set the response status code and send its string representation as the response body.

express.Router:

Use the express.Router class to create modular, mountable route handlers. A Router instance is a complete middleware and routing system; for this reason, it is often referred to as a “mini-app”.

and we can : -Use express.Router() multiple times to define groups of routes -Apply the express.Router() to a section of our site using app.use() -Use route middleware to process requests -Use route middleware to validate parameters using .param() -Use app.route() as a shortcut to the Router to define multiple requests on a route

example :

const express = require('express')
const router = express.Router()

// middleware that is specific to this router
router.use((req, res, next) => {
  console.log('Time: ', Date.now())
  next()
})
// define the home page route
router.get('/', (req, res) => {
  res.send('Birds home page')
})
// define the about route
router.get('/about', (req, res) => {
  res.send('About birds')
})

module.exports = router
Then, load the router module in the app:

const birds = require('./birds')

// ...

app.use('/birds', birds)

The app will now be able to handle requests to /birds and /birds/about, as well as call the timeLog middleware function that is specific to the route.

chained route

app.route() You can create chainable route handlers for a route path by using app.route().

example of chained route handlers app.route().

app.route('/book')
  .get((req, res) => {
    res.send('Get a random book')
  })
  .post((req, res) => {
    res.send('Add a book')
  })
  .put((req, res) => {
    res.send('Update the book')
  })