title: Is it possible to call several update query at once for Firestore via Cloud Functions?
body: <p>I am trying to update several documents in Firestore through a loop. It also creates many instances of update query so it is a messy solution when I try to listen to its changes on the client-side on the mobile app on Android and iOS and web client.</p>
  
  <pre><code>for (var item in ListOfData) {
      documentReference.update({
          SupportedCity: item
      })
      .then(function() {
          console.log("Document successfully updated!");
      })
      .catch(function(error) {
          // The document probably doesn't exist.
          console.error("Error updating document: ", error);
      });
  }
  </code></pre>
  
  <p>Thanks In Advance </p>