How to run multiple async functions then execute callback

Question

In my NodeJS code I need to make 2 or 3 API calls, and each will return some data. After all API calls are complete I want to collect all the data into a single JSON object

Answer 1

Sounds like async.parallel() would also do the job if you'd like to use async:

var async = require('async');

async.parallel({
    one: function(parallelCb) {
        request('http://www.example1.com', function (err, res, body) {
            parallelCb(null, {err: err, res: res, body: body});
        });
    },
    two: function(parallelCb) {
        request('http://www.example2.com', function (err, res, body) {
            parallelCb(null, {err: err, res: res, body: body});
        });
    },
    three: function(parallelCb) {
        request('http://www.example3.com', function (err, res, body) {
            parallelCb(null, {err: err, res: res, body: body});
        });
    }
}, function(err, results) {
    // results will have the results of all 3
    console.log(results.one);
    console.log(results.two);
    console.log(results.three);
});