Nested objects in javascript, best practices

Question

I would like to know the correct way to create a nested object in javascript. I want a base object called "defaultsettings". It should have 2 properties (object type): ajaxsettings and uisettings. I know that i can write something like

var defaultsettings = new Object();
var ajaxsettings = new Object();

defaultsettings.ajaxsettings = ajaxsettings.. etc.

But what i want to know is how to type it this way (that i suppose is a more correct way of doing it):

var defaultsettings = { 
    var ajaxsettings = { ... }
};

I suppose you get the idea. Thanks!

question from:https://stackoverflow.com/questions/7942398/nested-objects-in-javascript-best-practices

Answer 1

If you know the settings in advance you can define it in a single statement:

var defaultsettings = {
                        ajaxsettings : { "ak1" : "v1", "ak2" : "v2", etc. },
                        uisettings : { "ui1" : "v1", "ui22" : "v2", etc }
                      };

If you don't know the values in advance you can just define the top level object and then add properties:

var defaultsettings = { };
defaultsettings["ajaxsettings"] = {};
defaultsettings["ajaxsettings"]["somekey"] = "some value";

Or half-way between the two, define the top level with nested empty objects as properties and then add properties to those nested objects:

var defaultsettings = {
                        ajaxsettings : {  },
                        uisettings : {  }
                      };

defaultsettings["ajaxsettings"]["somekey"] = "some value";
defaultsettings["uisettings"]["somekey"] = "some value";

You can nest as deep as you like using the above techniques, and anywhere that you have a string literal in the square brackets you can use a variable:

var keyname = "ajaxsettings";
var defaultsettings = {};
defaultsettings[keyname] = {};
defaultsettings[keyname]["some key"] = "some value";

Note that you can not use variables for key names in the { } literal syntax.