express.js send json code example

Example 1: node js return json

var http = require('http');

var app = http.createServer(function(req,res){
    res.setHeader('Content-Type', 'application/json');
    res.end(JSON.stringify({ a: 1 }));
});
app.listen(3000);

// > {"a":1}

Example 2: node express post request json

var express = require('express');

var app = express();

app.use(express.json()); // built-in middleware for express

app.post('/', function(request, response){
 	let myJson = request.body;      // your JSON
	let myValue = request.body.myKey;	// a value from your JSON
	response.send(myJson);	 // echo the result back
});

app.listen(3000);