cors error in node js express

1var express = require('express')
2var cors = require('cors')
3var app = express()
4
5app.use(cors())
6
7app.get('/products/:id', function (req, res, next) {
8  res.json({msg: 'This is CORS-enabled for all origins!'})
9})
10
11app.listen(80, function () {
12  console.log('CORS-enabled web server listening on port 80')
13})
14

1app.use(function(req, res, next) {
2  res.header("Access-Control-Allow-Origin", "YOUR-DOMAIN.TLD"); // update to match the domain you will make the request from
3  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
4  next();
5});

1// CORS (Cross-Origin Resource Sharing) headers to support Cross-site HTTP requests
2
3app.all('*', function(req, res, next) {
4       res.header("Access-Control-Allow-Origin", "*");
5       res.header("Access-Control-Allow-Headers", "X-Requested-With");
6       res.header('Access-Control-Allow-Headers', 'Content-Type');
7       next();
8});
9

1//Cors = Cross-origin resource sharing
2
3var express = require('express');
4var cors = require('cors');
5var app = express();
6
7app.use(cors());
8
9var corsOptions = {
10  origin: 'http://example.com',
11  optionsSuccessStatus: 200 // some legacy browsers (IE11, various SmartTVs) choke on 204
12}
13
14app.listen(80, function () {
15  console.log('CORS-enabled web server listening on port 80')
16})

1var cors = require('cors')
2
3var app = express()
4app.use(cors())