async-parallel-example.js

async.parallel([
  function(callback) {
    setTimeout(function() {
      console.log('Task One');
      callback(null, 1);
    }, 200);
  },
  function(callback) {
    setTimeout(function() {
      console.log('Task Two');
      callback(null, 2);
    }, 100);
  }
],
function(err, results) {
  console.log(results);
  // the results array will equal [1, 2] even though
  // the second function had a shorter timeout.
});

// an example using an object instead of an array
async.parallel({
  task1: function(callback) {
    setTimeout(function() {
      console.log('Task One');
      callback(null, 1);
    }, 200);
  },
  task2: function(callback) {
    setTimeout(function() {
      console.log('Task Two');
      callback(null, 2);
    }, 100);
    }
}, function(err, results) {
  console.log(results);
  // results now equals to: { task1: 1, task2: 2 }
});