async-race-example.js

async.race([
  function (callback) {
    setTimeout(function () {
      callback(null, 'one');
    }, 300);
  },
  function (callback) {
    setTimeout(function () {
      callback(null, 'two');
    }, 100);
  },
  function (callback) {
    setTimeout(function () {
      callback(null, 'three');
    }, 200);
  }
],
  // main callback
  function (err, result) {
    // the result will be equal to 'two' as it finishes earlier than the other 2
    console.log('The result is ', result);
  });