title: Add a value to a list in Firebase?
body: <p>I currently have a JSON object that is structured like this:</p>
  
  <pre><code>"users": {
      "0":
          {
          "items_list": {
              "0": [1],
              "1": [2,3],
              "2": [8, 9, 10],
              "3": [11, 12, 13]
              },
          "name": "Dana"
          }
      },
  </code></pre>
  
  <p>Upon pressing a button in a React-Native app, I want to add a value to the array of attributes stored for one of the keys in the items_list. </p>
  
  <p>Specific example: Adding the number '14' to item '3', so that it will become "3": [11, 12, 13, 14]. </p>
  
  <p>Is there a way to just add a single value to an array without rewriting the whole thing? It seems like I may have to get the value of the array associated with a key, add a new value to it, and then push the whole thing back, but I wanted to check if there's a simpler way to go about doing this. Thanks!</p>