Question

145

Nested objects in javascript, best practices

rated 0 times [ 148] [ 3] / answers: 1 / hits: 147243 / 13 Years ago, sat, october 29, 2011, 12:00:00

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!

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jaredsages

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answered 13 Years ago morrismilom · Accepted Answer

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.