Converting strings like document.cookie to objects

Question

I have a string similiar to document.cookie:

var str = 'foo=bar, baz=quux';

Converting it into an array is very easy:

str = str.split(', ');
for (var i = 0; i < str.length; i++) {
    str[i].split('=');
}

It produces something like this:

[['foo', 'bar'], ['baz', 'quux']]

Converting to an object (which would be more appropriate in this case) is harder.

str = JSON.parse('{' + str.replace('=', ':') + '}');

This produces an object like this, which is invalid:

{foo: bar, baz: quux}

I want an object like this:

{'foo': 'bar', 'baz': 'quux'}

Note: I've used single quotes in my examples, but when posting your code, if you're using JSON.parse(), keep in your mind that it requires double quotes instead of single.

---

Update

Thanks for everybody. Here's the function I'll use (for future reference):

function str_obj(str) {
    str = str.split(', ');
    var result = {};
    for (var i = 0; i < str.length; i++) {
        var cur = str[i].split('=');
        result[cur[0]] = cur[1];
    }
    return result;
}