I get "undefined" when I use return;

Question

I get a snapshot value that if I console.log it works but I when I return the value I get "undefined".

I tried changing variable and changing the return values and using await and async .

async function GetElements(element, place) {
firebase.database().ref().child(place).orderByChild("uid").equalTo(element).once('value', (snapshot) => {
    snapshot.forEach(function(childSnapshot) {
      Holder = childSnapshot.val();
    });
  }, (errorObject) => {
    console.log("User does not exist");
    document.cookie = "uid=; Path=/; Expires=Thu, 01 Jan 1970 00:00:01 GMT";
    window.location.replace("login.html");
  });
  return Holder;
}
async function Test() {
  var bob = await GetElements("POkHi19eyZTfdeYECVpZByeVv2R2", "users/");
  console.log(bob)
}
Test()

Answer 1

You could try this:

async function GetElements(element,place) {
  firebase.database().ref().child(place).orderByChild("uid").equalTo(element).once('value', (snapshot) => {

    snapshot.forEach(function(childSnapshot) {
            
      Holder = childSnapshot.val();
      
    });

    return Holder;
  }, (errorObject) => {
    console.log("User does not exist");
    document.cookie = "uid=; Path=/; Expires=Thu, 01 Jan 1970 00:00:01 GMT";
    window.location.replace("login.html");
  });
}

This way, the return statement will only be executed after the callback function has been called and "Holder" has been set to the correct value.