//Runing loop from 0 to 4 for (int i = 0; i < 5; i++) { //Creating a node with the name of user0, user1, user2, user3 and user4 at each iteration DatabaseReference myRef = database.getReference("User" + i); //Creating a user object and appending i to all of its attributes. User user = new User("userName" + i, "abc" + i, "xyz" + i, "day" + i, "month" + i, "year" + i); //Writing each user to Firebase Realtime Database myRef.setValue(user); }