What is the most efficient way to deep clone an object in JavaScript? -

what efficient way clone javascript object? i've seen obj = eval(uneval(o)); being used, that's non-standard , supported firefox.

i've done things obj = json.parse(json.stringify(o)); question efficiency.

i've seen recursive copying functions various flaws.
i'm surprised no canonical solution exists.

note: reply answer, not proper response question. if wish have fast object cloning please follow corban's advice in answer question.

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i want note .clone() method in jquery clones dom elements. in order clone javascript objects, do:

// shallow copy var newobject = jquery.extend({}, oldobject);  // deep copy var newobject = jquery.extend(true, {}, oldobject); 

more information can found in jquery documentation.

i want note deep copy smarter shown above – it's able avoid many traps (trying deep extend dom element, example). it's used in jquery core , in plugins great effect.