title: Display a sum of value in json in React.js
body: <p>I have this json and I would like to view a sum of available_funds in my Component in React.js. If is this possible? could I ask for an example of viewing this? Because I can not do it.</p>
  
  <pre><code>[
    {
      id: 1,
      id_owner: 1,
      account_bill: 123456789,
      available_funds: 100
    },
    {
      id: 2,
      id_owner: 1,
      account_bill: 111111111,
      available_funds: 20
    }
  ]
  </code></pre>
  
  <p>React.js component:</p>
  
  <pre><code>class AvailableFunds extends Component {
    constructor() {
      super();
      this.state = {
        availableFunds: '',
        isLoading: true,
      };
    }
  
    componentDidMount() {
      axios
        .get('http://localhost:3000/api/bills/1')
        .then(({ data }) =&gt; {
          console.log(data);
          this.setState({
            availableFunds: data.available_funds,
            isLoading: false
          });
        })
        .catch(err =&gt; {});
    }
  </code></pre>
  
  <p>...?</p>