Which function is used for users to listen monitor for changes in the Firebase?

Launch Android Studio and create a new Flutter project.

For reading a data from the Firebase Realtime database, Firebase has two methods on() and once() . on() method to retrieve data . This method is taking the event type as “value” and then retrieves the snapshot of the data. When we add val() method to the snapshot, we will get the JavaScript representation of the data.

Inside the value field, you can add any data you want. This will be the string which we are going to display inside our text view. After adding data click on the add button and your data will be added in Firebase and this data will be displayed in your app.

Firebase data is retrieved by either a one time call to GetValueAsync() or attaching to an event on a FirebaseDatabase reference . The event listener is called once for the initial state of the data and again anytime the data changes.