Question

I’d like to create JavaScript object on the fly using javascript object initializer notation, but take keys from config, so instead of

var obj = {
  'key' : 'some value'
};

I’d like to have:

var config = {
  myKeyName: 'key'
};

var obj = {
  config.myKeyName : 'some value' // this will not work, just to illustrate
};

The question is how to place value of config.myKeyName in this situation.

Is this possible?

Edit: I’m aware of using indexing ([]), but that’s not an option in case of deeply nested objects.

Answer 1

From your comments and edit, your question seems to be: For deeply nested objects, can I have the keys be dynamic but still have the object initializer syntax.

E.g., not:

var key1 = "a", key2 = "b", key3 = "c", obj;
obj = {}
obj[key1] = {};
obj[key1][key2] = {};
obj[key1][key2][key3] = 42;

But

var obj = {
    /*magic here using key1 to get "a"*/: {
        /*magic here using key2 to get "b"*/: {
            /*magic here using key3 to get "c"*/: 42
        }
    }
};

The answer is no, there isn’t any way to do that except eval. The keys in an object initializer cannot be derived from variables. The [] notation is the best option for using a string to define a property name (the only other option I can see is Object.defineProperty which would be far worse and is ES5-only). For your deeply-nested structures, it sounds like you’re going to want a recursive factory function of some kind.