how to get object's name in javascript?

Question

For example I have such an object:

var a = {
    'light': 'good',
    'dark' : {
        'black': 'bad',
        'gray' : 'not so bad'
    }
}

and such a code:

var test = function(obj) {
    // do smth with object
    // I need to get obj's name ('dark' in my way)
}
test(a.dark);

How to get name of object in function's body. So I mean I should know that obj's name is 'dark'.

I've tried inspect object with firebug, but it's only show object's property. It's not showing some internal methods or properties, with which I'll be able to know

Thank you.

Answer 1

You can't. You're only passing the object { black : 'bad', gray : 'not so bad' } into test. This object does not intrinsically have the name "dark", it's just an object that happened to exist as the property dark of the object a. This information is irretrievably lost when passing it into a function.

You're basically trying to retrieve the variable name that held the value before the value got passed into the function. That's not possible.