title: React Native Download multiple JSON and combine
body: <p>I am trying to download multiple JSON and combine them together in the variable and display them in a flatlist. But I am only seeing contents from only 1 JSON. How do we do multiple download and combine the result ? Is there a better way to do this ? Am I downloading it the correct way ?</p>
  <pre><code>export default class CategoryScreen extends Component {
  
      constructor(props) {
          super(props);
          this.state = {
              isLoading: true,
              dataSource: [],
              AllNews: [],
          }
      }
    
      componentDidMount(){
          this.GrabData('http://hunterdata.serveblog.net/t-computerworld.json');
          this.GrabData('http://hunterdata.serveblog.net/t-thestar.json');
      }
  
      
      async GrabData(TheURL) {
        let tmpData = [];
        try{
          const response = await fetch(TheURL, {headers: {'Cache-Control' : 'no-cache'}});
          const data = await response.json();
          tmpData = data;
          if ((this.state.dataSource.length) = 0) {
            this.setState({ dataSource: tmpData });
          } else {
            let tmpData1 = this.state.dataSource;
            tmpData = [...tmpData1, ...data];
            this.setState({ isLoading: false, dataSource: tmpData})
          }        
        } catch (error) {
          console.error(error);
        }
      }
          
  
      render() {
          if (this.state.isLoading) {
              return (
                  &lt;View&gt;
                      &lt;ActivityIndicator /&gt;
                  &lt;/View&gt;
              )
          } else {
  
            let mydata = this.state.dataSource;
              return (       
              &lt;View style={styles.container}&gt;
              &lt;FlatList
                data={mydata}
                renderItem={({item}) =&gt; &lt;Text style={styles.text}&gt;{item.title}&lt;/Text&gt;}
                /&gt;
              &lt;/View&gt;            
              );
              
          }
      }
  } 
  </code></pre>