gistfile1.js

    componentDidMount() {
        axios.get('https://hacker-news.firebaseio.com/v0/topstories.json?print=pretty')
            .then(response => {
                let posts = [];
                const lastPostIndex = response.data.length - 1;
                for (var i = 0; i < response.data.length; i++) {
                    axios.get('https://hacker-news.firebaseio.com/v0/item/' + response.data[i] + '.json?print=pretty')
                            .then(post => {
                                posts.push(post.data);
                                if (i === lastPostIndex) {
                                    this.setState({posts});
                                }
                            });
                }
            });
    }