Say Hello {name} or Hello World.

hello-name.js

'use strict'

const express = require('express')
const app = express()

const PORT = process.env.PORT || 3000

function capitalize (str) {
  const firstLetter = str.charAt(0) // we can check what's inside here
  return `${firstLetter.toUpperCase()}${str.slice(1)}`
}

app.get('/:name?', (req, res) => {
  const name = req.params.name ? capitalize(req.params.name) : 'World'
  res.send(`Hello ${name}!`)
})

app.listen(PORT, () => console.log(`App listening on *:${PORT}`))