How to use DontDestroyOnLoad only once

Questions & Answers
1

Hello everyone.
I am trying to create single player and multiplayer modes that you select in a menu scene using buttons. When you press the multiplayer button, a multiplayer boolean is set to true and the same goes for single player. I need those boolean values to stay the same when loading the game scene, so I used DontDestroyOnLoad on the gameObject holding the script. My issue is that when I load back the menu scene, it creates duplicates of the gameObject holding the singleplayer or multiplayer script. I managed to prevent that by destroying any new instance of the gameObject. However doing it this way unlinks the buttons from the script and it is then impossible to change player modes after reloading the menu scene once. So what I want to do is instead of removing any new instance of the gameObject, I want to destroy the old one which is not linked to the freshly loaded buttons or make the DontDestroyOnLoad only work once and have the gameObject destroyed when reloading the menu scene.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Joueurs : MonoBehaviour
{

    public static Joueurs Instance;

    public bool solobool;
    public bool soloiabool;
    public bool multijoueurbool;

    void Awake()
    {

        solobool = true;

        
        if (Instance == null)
        {
            Instance = this;
            DontDestroyOnLoad(gameObject);
        }
        else if (Instance != this)
            Destroy(gameObject);
    }



  public void solo()
    {
        solobool = true;
        soloiabool = false;
        multijoueurbool = false;
    }



    public void soloia()
    {
        solobool = false;
        soloiabool = true;
        multijoueurbool = false;
    }

    public void multijoueur()
    {
        solobool = false;
        soloiabool = false;
        multijoueurbool = true;
    }
}
2

@jangouu You could remove the need for the don’t destroy on load altogether and just use player prefs.

PlayerPrefs.SetInt("solobool", 0); // 0 = false, 1 = true
PlayerPrefs.SetInt("soloiabool", 0);
PlayerPrefs.SetInt("multijoueurbool", 0);

then read it back with:

if (PlayerPrefs.HasKey("solobool")) {
  bool solobool = PlayerPrefs.GetInt("solobool") == 1;
}

and with this you can access player prefs from any scene or script.