Retrieving Postal Code with Google Maps Javascript API V3 Reverse Geocode

You can do this pretty easily using the underscore.js libraray: http://documentcloud.github.com/underscore/#find

_.find(results[0].address_components, function (ac) { return ac.types[0] == 'postal_code' }).short_name

Using JQuery?

var searchAddressComponents = results[0].address_components,
    searchPostalCode="";

$.each(searchAddressComponents, function(){
    if(this.types[0]=="postal_code"){
        searchPostalCode=this.short_name;
    }
});

short_name or long_name will work above
the "searchPostalCode" var will contain the postal (zip?) code IF and only IF you get one from the Google Maps API.

Sometimes you DO NOT get a "postal_code" in return for your query.

What I've realized so far is that in most cases the ZIPCODE is always the last value inside each returned address, so, if you want to retrieve the very first zipcode (this is my case), you can use the following approach:

var address = results[0].address_components;
var zipcode = address[address.length - 1].long_name;