Express/Node

anonymous·2021년 9월 11일

What is Node?

open-source, cross-platform runtime environment
allows the creation of server-side tools and applications in JS.

Benefits of Node?

Great performance! Node was designed to optimize throughput and scalability in web applications and is a good solution for many common web-development problems (e.g. real-time web applications).
Code is written in "plain old JavaScript", which means that less time is spent dealing with "context shift" between languages when you're writing both client-side and server-side code.
JavaScript is a relatively new programming language and benefits from improvements in language design when compared to other traditional web-server languages (e.g. Python, PHP, etc.) Many other new and popular languages compile/convert into JavaScript so you can also use TypeScript, CoffeeScript, ClojureScript, Scala, LiveScript, etc.
The node package manager (NPM) provides access to hundreds of thousands of reusable packages. It also has best-in-class dependency resolution and can also be used to automate most of the build toolchain.
Node.js is portable. It is available on Microsoft Windows, macOS, Linux, Solaris, FreeBSD, OpenBSD, WebOS, and NonStop OS. Furthermore, it is well-supported by many web hosting providers, that often provide specific infrastructure and documentation for hosting Node sites.
It has a very active third party ecosystem and developer community, with lots of people who are willing to help.

Hello Node

1 Open terminal
2 Go to Project Directory
3 Make file for loading node

// Load HTTP module
const http = require("http");

const hostname = "127.0.0.1";
const port = 8000;

// Create HTTP server
const server = http.createServer((req, res) => {

   // Set the response HTTP header with HTTP status and Content type
   res.writeHead(200, {'Content-Type': 'text/plain'});

   // Send the response body "Hello World"
   res.end('Hello World\n');
});

// Prints a log once the server starts listening
server.listen(port, hostname, () => {
   console.log(`Server running at http://${hostname}:${port}/`);
})

4 Go to teriminal and run file in node

node hello.js

5 Result in http://127.0.0.1:8000/

What is Expresss?

Popular Node Web Framework
Writes handlers for requests with different HTTP verbs at different URL paths (routes).
Integrate with "view" rendering engines in order to generate responses by inserting data into templates.
Set common web application settings like the port to use for connecting, and the location of templates that are used for rendering the response.
Add additional request processing "middleware" at any point within the request handling pipeline.

Hello World Express

1 Create DIR for Running Express

npm init
npm install express --save

2 Create new file named app.js

//(imports) the express module and create an Express application
const express = require('express');
const app = express();
const port = 3000;

// app.get shows route definition
app.get('/', (req, res) => {
  res.send('Hello World Express!')
});

//starts up the server on a specified port ('3000') and prints a log comment
app.listen(port, () => {
  console.log(`Example app listening on port ${port}!`)
});