Keep Singleton while creating holder GameObject at runtime?

Question

I used the persistence tutorial to create SIngleton of my game state object and it all works well. I also found that I need to create manually GameObject on scene, so that I have where to attach the game state script. Then I got to idea, what if I create the holder object at runtime using "new GameObject()" and than "AddComponent()" function. Is my Singleton pattern still kept across scenes or I am recreating this game state object every time I enter a new scene?

Game state code:

 using UnityEngine;
 using System;
 using System.Runtime.Serialization.Formatters.Binary;
 using System.IO;
 
 public class SaveLoadGameData : MonoBehaviour 
 {
     public static SaveLoadGameData gameState;
     
     public float experience = 0;
     public float score = 0;
     
     void Awake () 
     {
         if (gameState == null) 
         {
             DontDestroyOnLoad(gameObject);
             gameState = this;
         }
         else if (gameState != this) 
         {
             Destroy(gameObject);
         }
     }
     
     public void Save ()
     {
         // saving code
     }
     
     public void Load ()
     {
         // loading code
     }
     
     public void ResetGameState ()
     {
         // reset data to defaults and save.
     }
 }
 
 [Serializable]
 class GameData
 {
     public float experience = 0;
     public float score = 0; 
 }

MyGameScene.cs file. All other scene scripts inherit from this class as it holds general stuff about each scene.

 // default class that includes all necessary stuff about each scene in general.
 // All other scene scripts inherit from this class.
 using UnityEngine;
 using UnityEngine.UI;
 
 public class MyGameScene : MonoBehaviour 
 {
     public Button PlayBtn;
     public Button HelpBtn;
     
     protected GameObject gameStateObject;
     protected SaveLoadGameData gameState;
     
     protected void Init ()
     {
         gameStateObject = new GameObject();
         gameStateObject.name = Helper.SAVE_LOAD_GAME_DATA_GAME_OBJECT;
         SaveLoadGameData.gameState = gameStateObject.AddComponent<SaveLoadGameData>();
         SaveLoadGameData.gameState.Load();
         gameState = SaveLoadGameData.gameState;
     }
     
     // other useful functions for the scene
 }

A scene inheriting from MyGameScene:

 using UnityEngine;
 using UnityEngine.UI;
 
 public class MainMenu : MyGameScene 
 {
     public Text gameTitle;
     public Text gameSubtitle;
     
     public Button newGameBtn;
     
     void Awake ()
     {
         Init();
     }
     
     // main menu functions etc...
 }

Answer 1

There's nothing generally wrong with this pattern, and in fact I use a variant of it myself fairly often.

Something else that I like to do, but I don't know if you'll find this valuable, is to use an accessor to dynamically create my singleton like this:

 //MySingletonScript could be any singleton, in this case the SaveLoadGameData script
 public static MySingletonScript Instance 
 {
     //Now, MySingletonScript.Instance will never return null!
     get {
         if(inst == null) inst = createInstance();
         return inst; 
     }
 }

 private static MySingletonScript inst;

 private static MySingletonScript createInstance() {
     GameObject gob = new GameObject("MySingletonScript instance");
     return gob.AddComponent<MySingletonScript>();
 }

Now, since you're abstracting away this process, your Init() method would just need to call SaveLoadGameData.Instance.Load();

Keep Singleton while creating holder GameObject at runtime?

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