A simple example showing how to use async to parallelize several invocations to asynchronous functions and wait for the result.

gistfile1.js

// A simple example showing how to use async to parallelize several invocations to asynchronous functions and wait for the result.
var async = require('async');

/**
 * A very simple asynchronous function which takes in a number and invokes the callback with that number incremented by 1.
 * @param number
 * @param cb(err, result)
 */
function addOne(number, cb) {
    process.nextTick(function() {
        cb(null, number + 1);
    });
}

/**
 * Takes in an array of numbers. Creates a number of callbacks and invokes async.parallel.
 * @param numbers
 * @param cb(err, result)
 */
function addOneToNumbers(numbers, cb) {
    var callbacks = [];
    numbers.forEach(function(number) {
        callbacks.push(async.apply(addOne, number));
    });
    async.parallel(callbacks, cb);
}


addOneToNumbers([1,2,3,4,5,6,7,8,9, 10], function(err, result) {
    console.log(err);
    console.log(result);
});