Quite wierd

gistfile1.js

addresses = _.sortBy(addresses, function(address) {
    addressEntity = address.address;
    var reducedKey;
    reducedKey = ['name', 'city', 'zipCode'].reduce(function(previous, current) {
        if (previous && addressEntity.hasOwnProperty(previous) && addressEntity[previous]) {
            return previous;
        } else if (current) {
            return current;
        }
    });
    return addressEntity[reducedKey];
});