How to save data in object in Javascript

Question

I have this object and I want to save data in the Obj.document.metadata.name example: newData = Obj.document.metadata.name
but it didn't work. I will appreciate all answers.

var Obj =
        {
            "document": {
                "metadata": {
                    "name": "",
                    "date": "",
                    "autor": ""
                 } 
             }
         }

Answer 1

Obj.document.metadata.name="Xerardoo"

temporarily you can save this way. But it will be lost if page refresh

Answer 2

你也可以这样

Obj["document"]["metadata"]["name"] = "Value"