Getting a json back from express.js using a jQuery get method does not work

Question

I am trying to pass a value as JSON from my back end to the front end of my application. I am currently running express.js and the connection for all post methods is PERFECT.

Upon a button click in the FRONT-END in my application I want to get back an invoice number from my server.

On the front end my code looks like this with jQuery:

$.get("/invoiceNumber", function(data) {
  console.log(data.number);
});

On the back end it looks like this:

app.get("/invoiceNumber", function(req, res) {
  res.json({ number: 4 });
});

Currently I am passing 4 just as a test.

The Error I am getting is:

GET http://127.0.0.1:3000/invoiceNumber 404 (Not Found)

If I try to go directly to:

http://127.0.0.1:3000/invoiceNumber

I get:

Cannot GET /invoiceNumber

Answer 1

it looks that this question is duplicated How to allow CORS?

So you can enable all cors requests with

npm install cors

your App.js

var express = require('express')
var cors = require('cors')
var app = express()

app.use(cors())

app.get('/products/:id', function (req, res, next) {
  res.json({msg: 'This is CORS-enabled for all origins!'})
})

app.listen(80, function () {
  console.log('CORS-enabled web server listening on port 80')
})

you can find additional information here https://expressjs.com/en/resources/middleware/cors.html#enable-cors-for-a-single-route

Answer 2

Looks to me like you need to refrence where you back end is running from:

$.get("/invoiceNumber", function(data) {
  console.log(data.number);
});

if your express app is running on port 3000, change your front end to the following:

$.get("localhost:3000/invoiceNumber", function(data) {
  console.log(data.number);
});