Iterating over every property of an object in javascript using Prototype?

Is there a way to iterate over every property of an object using the Prototype JavaScript framework?

Here's the situation: I am getting an AJAX response in JSON that looks something like this:

{foo: 1, bar: 2, barobj: {75: true, 76: false, 85: true}}

If I evaluate that json response in to a variable response, I want to be able to iterate over each property in the response.barobj object to see which indexes are true and which are false.

Prototype has both Object.keys() and Object.values() but oddly seems to not have a simple Object.each() function! I could take the results of Object.keys() and Object.values() and cross-reference the other as I iterate through one, but that is such a hack that I am sure there is a proper way to do it!

There's no need for Prototype here: JavaScript has for..in loops. If you're not sure that no one messed with Object.prototype, check hasOwnProperty() as well, ie

for(var prop in obj) {
    if(obj.hasOwnProperty(prop))
        doSomethingWith(obj[prop]);
}

You have to first convert your object literal to a Prototype Hash:

// Store your object literal
var obj = {foo: 1, bar: 2, barobj: {75: true, 76: false, 85: true}}

// Iterate like so.  The $H() construct creates a prototype-extended Hash.
$H(obj).each(function(pair){
  alert(pair.key);
  alert(pair.value);
});