_.pluckNested is a better implementation of _.pluck from underscore.js

pluckNested.js

// Convenience version of a common use case of `map`: fetching a property. 
// The property can be nested using "." notation.
// _.pluckNested([{a:{z:1}},{a:{z:2}}],"a.z") ==> [1, 2]
_.pluckNested = function(obj, key) {
    var objKey = key.split('.');
    return _.map(obj, function(o) {
        var value = o, item;
        _.each(objKey, function(key) {
            if(_.isObject(value[key])) {
                value = value[key];
            } else {
                item = value[key];
            }
        });
        return item;
    });
};