Preferred way of creating "dictionary of dictionaries" in JavaScript

Question

Assume that I need a JavaScript dictionary (object/ associative array) which I need to access as follows:

var value = dict[foo][bar][buz][qux]; // this could go on

Which is the best way to initialize this dictionary? The only way I can think of is:

// 'foo', 'bar', 'baz', 'qux' are variables
var dict = {};
dict[foo] = {};
dict[foo][bar] = {};
dict[foo][bar][buz] = {};
dict[foo][bar][buz][qux] = value;

Alternatively, is there a better way of achieving the same results? I would prefer a solution that works both in browsers and Node.js.

Answer 1

An option is to build the object dynamically, like:

var vals = [1, 2, 3, 4];

function createObject(arr) {
    var obj = {};
    var mod = obj;
    for (var i = 0, j = arr.length; i < j; i++) {
        if (i === (j - 1)) {
            mod.value = arr[i];
        } else {
            mod[arr[i]] = {};
            mod = mod[arr[i]];
        }
    }
    return obj;
}

console.log(createObject(vals));

DEMO: http://jsfiddle.net/BnkPz/

So your list of variables would have to be put into an array and passed to the function, or the function could modified to work with any number of passed arguments.