Question: ```js
import VersionReducer from "./VersionReducer";

export default combineReducers({
    appVersion: VersionReducer
});

```

In my VersionReducer.js file

When I use the following, everything is fine

```js
export default () => [{
    versionNumber: 22,
    versionName: "2.2"
}];

```

But I want to get object from this. like this

```js
export default {
    versionNumber: 22,
    versionName: "2.2.1"
};

```

Answer: 
The `update()` method interprets the `.` as addressing a nested field. So `a.b.c` would be a field `c` inside a field `b` inside field `a`. 

There is no way (that I know of) to prevent Firestore from interpreting the `.` in calls to `update()`. Luckily calls to `set()` are not interpreted in the same way, and you can use `set` combined with `merge: true` to get the same update behavior without it interpreting dots.

```
db.collection('collection').doc('doc').set({ [key] : value }, { merge: true })

```
The problem of using `.` in a field ID is that it require escaping like said in the [firestore documentation](https://firebase.google.com/docs/firestore/best-practices#field_names)

So if you really want the dot you should escape it like so `\.` because if you don't firestore understand `A.B` like the item of key `B` in the map of key `A`.

Another solution if you can limit the decimals of your float key is to transform your float into an integer so you do not have the problem of the dot notation.

For example if you can have only 2 decimals: `2.22` will be `222` (`2.22 * 100`).