backend practice

.gitignore

+node_modules/
+package-lock.json
+

app.js

+const express = require('express')
+const app = express()
+const port = 3000
+
+app.get('/', (req, res) => {
+  res.send('Hello World!')
+})
+
+app.listen(port, () => {
+  console.log(`Example app listening at http://localhost:${port}`)
+})

package.json

+{
+  "name": "backend_lesson",
+  "version": "1.0.0",
+  "description": "pr-coding backend lesson",
+  "main": "app.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [
+    "pr-coding",
+    "backend"
+  ],
+  "author": "jyc",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.17.1"
+  }
+}