Namespaces in JavaScript

namespace.js

/**
 * Registers the specified namespace, ensuring all parts of the namespace are created. If the namespace
 * already exists, it will not be modified.
 *
 * Usage:
 * namespace('foo.bar');
 * foo.bar.baz = 'qux';
 *
 * @param {String} namespace The namespace to register. Namespaces are hierarchal, and are separated by dots.
 */
window.namespace = function(namespace) {
    var parts = namespace.split(".");
    var root = window;

    for(var i=0; i<parts.length; i++) {
        root = root[parts[i]] = root[parts[i]] || {};
    }
};