jQuery extend nested object -

when try extend object, passing in full object, seems overwrite desired target object. however, can extend each subobject individually, , pass in , works.

$(function() {     window.test = {};     $.extend(window.test, {         init: function(opts1, opts2) {             //method 1, overwrites                         this.options = $.extend({}, this.settings, {opts1: opts1, opts2: opts2});              //method 2, works             this.a = $.extend({}, this.settings.opts1, opts1);             this.b = $.extend({}, this.settings.opts2, opts2);             this.options2 = $.extend({}, this.settings, {opts1: this.a, opts2: this.b});              console.log(this.options, this.options2);         },         settings: {             opts1: {                 a: 'hello',                 b: 'hi',                 e: 'this still here?'             },             opts2: {                 c: 'yo',                 d: 'wassup'             }         }     });     test.init({ a: 'hello2', b: 'hello3' }); }); 

my question if there way utilize first method (a 1 line, simple method) achieve results of second method (individual subobjects).

also, here's jsfiddle.

you can deep-copy extends passing true first parameter $.extend. believe asking here.

this.options = $.extend(true, this.settings, {opts1: opts1, opts2: opts2}); 

see second definition in documentation.