I have an error like this one in my console :

> 
> Objects are not valid as a React child (found: object with keys {id,
>  marketId, title, picture, language, flag, completed, date, rate,
>  categories}). If you meant to render a collection of children, use an
>  array instead.
> 
> 
> 

this is my data in back :

```
const demoCompletedData = [
  {
    id: 1,
    marketId: "1111-1111-1111-1111",
    title: "Autonomous car",
    picture: "https://th?id=OIP.fdvfdvfdvfdvfd&pid=Api",
    language: "English",
    flag: "",
    completed: true,
    date: "22/01/2019 10:30",
    rate: 9.1,
    categories: {
      de: 1,
      sp: 2,
      uk: 0,
      fr: 1,
      us: 4,
    },
  },

```

and my code in front I use redux :

```
  fetchDemo() {
    this.props.demoFetchRequest();
    const { marketId } = this.props.match.params;
    axios.get(`/api/v1/passport-authenticate/market/${marketId}`)
      .then((res) => { return res.data; })
      .then(demo => this.props.demoFetchSuccess(demo))
      .catch(error => this.props.demoFetchError(error));
  }

```

my code in render :

```
const { demo } = this.props;

```

and my code in return :

```
{demo}

```

How can map the key categories and read its value ?