Your task is to create a webserver calculator using Express routes. Your calculator should handle GET (app.get()) requests to /add, /subtract, /multiply and /divide. You should use URL parameters to handle requests to your calculator.

Example using URL parameters:

This is an example of a simple GET route with request parameters using express:

app.get('/:input', (req, res) => {
  console.log("req.params: ", req.params)
  res.send("Our parameter is " + req.params.input + ".");
})

• fork and clone this repo and then cd in into express-routes-calc
• run npm init to initialize a node project
• run npm i express to install the required packages
• touch index.js to create the main entry point for your express app
• use nodemon to run your express app

Before writing your routes, set up a simple express app with a hello world route to test that everything is working.

// import required modules

// configure express app

// define routes

// listen on a port

// import required modules
const express = require('express')

// configure express app
const app = express()
const PORT = 3000

// define routes
app.get('/', (req, res) => {
  res.send('Hello, World!')
});

// listen on a port
app.listen(PORT, () => {
  console.log(`listening to the smooth sounds of port ${PORT} in the morning 🌊`)
})

Make it so your calculator can accept any amount of numbers to do math with instead of just 2 hardcoded ones with the wildcard * route variable. Instead if having the the math operation as the first route parameter, send it in the query params, so one route can handle addition, subtraction, multiplication, and division.

For example the URL /5/6/7/8?math=add would respond with 26 and the URL 5/6/7/8?math=subtract would respond with -16. Likewise 5/6/7/8/9/10?math=add should respond with 45 and so on.

Use this example at /* to experiment with how this might work:

app.get("/*", (req, res) => {
  console.log(req.params)
  res.send(req.params)
})

Follow along with the gitbook notes on express routing for some tips and tricks.

1. All content is licensed under a CC-BY-NC-SA 4.0 license.
2. All software code is licensed under GNU GPLv3. For commercial use or alternative licensing, please contact [email protected].