title: react native using asyncStorage for daily journaling and charting
body: <p>I'm creating a prototype app for a client and it's mainly concerned with self journaling and graphing. Say I wanted to enter how many calories I ate today and how many calories I burned, I would have a screen with two inputs where I could save those numbers for myself along with today's date.</p>
  
  <p>I'm wondering how I can use asyncStorage like this with the date so that any user can have the data specific to their device/phone and they can journal every day but I can use the data (by date) to show on a graph for them. Basically, if they saved calories in/calories out every day for a week the graph would be able to show the data for each day of that week on their device.</p>
  
  <p>I have a very basic example of that here:</p>
  
  <pre><code>async storeItem(key, item) {
  try {
      var jsonOfItem = await AsyncStorage.setItem(key, JSON.stringify(item));
      return jsonOfItem;
  } catch (error) {
    console.log(error.message);
  }
  }
  </code></pre>
  
  <p>But how can I do this with keys like 'caloriesIn' and 'caloriesOut' as well as the current date with each?</p>