Quiero preguntar cómo podemos eliminar datos de la base de datos en tiempo real de Firebase después de una cierta cantidad de mensajes usando javascript.

El código:

 function getData() { firebase.database().ref("/" + room_name).on('value', function (snapshot) { document.getElementById("output").innerHTML = ""; snapshot.forEach(function (childSnapshot) { childKey = childSnapshot.key; childData = childSnapshot.val(); if (childKey != "Purpose") { firebase_message_id = childKey; message_data = childData; //Start code named = message_data["name"]; message = message_data["message"]; like = message_data["like"]; timed= message_data['time'] row = "<h4> "+ named+"<b class='time'> "+timed+"</b>"+"</h4><h4 class='message_h4'>"+ message +"</h4><button class='btn btn-warning' id='"+firebase_message_id+"' value='"+like+"' onclick='updateLike(this.id)'><span class='glyphicon glyphicon-thumbs-up'> Like: "+ like +"</span></button><hr>"; document.getElementById("output").innerHTML += row; //End code var objDiv = document.getElementById("output"); objDiv.scrollTop = objDiv.scrollHeight; } }); }); } getData();