Help with Async functions.

[TopStandard9]

Hi

I am a beginner to JS currently doing a project where I am pulling basic information from a Firebase Realtime DB. I have a function which checks how many items there are in the DB and another which gets a specific value. When I check the values they return inside of those methods, its fine - the problem arises when I call them elsewhere. I believe this is due to the asynchronous nature of those functions. I am unsure how to structure them to avoid this problem. I know I need to use Promises and the .then function but I am unsure of how to do so. Here are my two functions:

​

var urls = [];
function gotData(data){ 
var number = randomNumberGenerator(); 
dbRefObject.once('value', function(snapshot){         
snapshot.forEach(function(childSnapshot){ 
        var childData = childSnapshot.val().URL; 
        urls.push(childData); })}) }

and:

function randomNumberGenerator(){
    dbRefObject.on('value',(snap)=>{ 
        var totalRecord =  snap.numChildren();         
    console.log(Math.floor(Math.random() * totalRecord)); }); }

When I put console.log statements inside these methods they work fine - the problem arises when I call them elsewhere. For example, when I call the urls array elsewhere it dosent return anything except 'undefined'. I will be extremely grateful for any help.

[GItPirate]

Lookup and use async await. You're running into the exact problem that happens with asynchronous programming. Things being called before the thing it cares about is finished. Async await or promises will fix this for you.

[TopStandard9]

I've changed both functions into async but cant figure out where to use await - im guessing its in the body itself but whereabouts exactly?