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What is the most efficient way to clone a JavaScript object? I've seen:

Suppose I have the following object in JavaScript: var object = { "key1": "value1", "key2": "value2", "key3": "value3" }; How do I find out how many values exist in the object? Source: Tips4all

Just cant figure it out. I have a large object stored as a JSON file and I want to access it once and use it multiple times: var myjson = new Object(); $.getJSON("myJSON.js", function(json) { myjson = JSON.stringify(json); }); $('#console').append(myjson); This does nothing. It's a scope issue, I know. I just don't know how to do what I'm wanting. Must I do all my functions inside the $.getJSON call or is there a way to pass the object that I can use throughout runtime?

This is probably pretty easy, yet I am confused, so maybe I might still learn something more today. I am trying to do the following: var myObj = {}; myObj.src = {} myObj.src.A = ['1.png','2.png','3.png']; myObj.A = new Image(); myObj.A.src = this.src.A[0]; This will result in an Uncaught TypeError: Cannot read property 'A' of undefined error. When I use myObj.src.A[0] instead of this it is working fine. What would be the correct way to use this in this context?

I'm talking about methods like this: $object->method()->method1('param')->method2('param'); Those are created by returning the object in the function. return $this; I've seen third-party software use that method, but I'm wondering, wouldn't that cause a bit of a problem with the resources or memory because you're continuously returning the entire object?