function parseFormUrlEncodedString(serializedFormData) {
    var decodedFormData = decodeURIComponent(serializedFormData.replace(/\+/g, " "));
    var pairs = decodedFormData.split('&');
    var target = {};

    var whatIsNext = function(memberAccessIndex, arrayAccessIndex) {
        if (memberAccessIndex > -1 && arrayAccessIndex > -1) {
            if (memberAccessIndex < arrayAccessIndex) {
                return 'object';
            } else {
                return 'array';
            }
        }
        else if (memberAccessIndex > -1) {
            return 'object';
        } else if (arrayAccessIndex > -1) {
            return 'array';
        }

        return 'primitive';
    };

    var addPair = function(pair, obj) {
        var currentSplit = pair.split('=');

        if (currentSplit.length === 2) {
            var name = currentSplit[0];
            var value = currentSplit[1];
            var memberAccessIndex = name.indexOf('.');
            var arrayAccessIndex = name.indexOf('[');
            var nextItem = whatIsNext(memberAccessIndex, arrayAccessIndex);

            if (nextItem === 'object') {
                // Nested object
                name = name.substring(0, memberAccessIndex);

                if (!obj[name]) {
                    obj[name] = {};
                }

                addPair(pair.substring(memberAccessIndex + 1), obj[name]);
            } else if (nextItem === 'array') {
                // Array
                var index = name.substring(arrayAccessIndex + 1, name.indexOf(']'));
                name = name.substring(0, arrayAccessIndex);

                if (!obj[name]) {
                    obj[name] = [];
                }

                var arr = obj[name];

                if (memberAccessIndex > -1) {
                    // Array of objects
                    if (!arr[index]) {
                        arr[index] = {};
                    }

                    addPair(pair.substring(memberAccessIndex + 1), arr[index]);
                } else {
                    // Array of primitives
                    arr[index] = value;
                }
            } else {
                // Primitive
                obj[name] = value;
            }
        }
    };

    pairs.forEach(function(pair) {
        addPair(pair, target);
    });

    return target;
}

var objWithArray = parseFormUrlEncodedString('names[0]=Larry&names[1]=Moe&names[2]=Curly');
var objWithNestedObj = parseFormUrlEncodedString('car.make=Saturn&car.model=SL2&car.year=1998&car.engine.power=125 HP&car.engine.type=4C DOHC');
var objWithArrayOfObj = parseFormUrlEncodedString('car[0].make=Saturn&car[0].model=SL2&car[0].year=1998&car[0].engine.power=125 HP&car[0].engine.type=4C DOHC&car[1].make=Saturn&car[1].model=SL1&car[1].year=1999&car[1].engine.power=100 HP&car[1].engine.type=4C');