using async-loop

async-loop2.js

const req = require("request")
let calls = [
function (cb) {
  req.get('http://www.google.com', cb)
},
function (cb) {
  req.get('http://www.yahoo.com', cb)
},
function (cb) {
  req.get('http://www.msdn.com', cb)
}
]

asyncLoop(calls, (err, results) => {
  if(err) { 
    return console.log("There was a problem executing one of the calls: ", err)
  }
  console.log("There are ", results.length, "sets of results")
})