Unity3D - When is "DontDestroyOnLoad object" destroyed?

Question

Am I have to destroy it before turn off the application? or after quit GB collect them?

How Does DontDestroyOnLoad works? has a ref count stuff?

Answer 1

Objects instantiatied in a scene are (by default) destroied when a new scene (level) is loaded. Using DontDestroyOnLoad you are telling to NOT follow this behaviour, so that the object will be persistent among levels. You can always delete it by calling Destroy() function.

From the documentation:

Makes the object target not be destroyed automatically when loading a new scene. When loading a new level all objects in the scene are destroyed, then the objects in the new level are loaded. In order to preserve an object during level loading call DontDestroyOnLoad on it. If the object is a component or game object then its entire transform hierarchy will not be destroyed either.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Awake() {
        DontDestroyOnLoad(transform.gameObject);
    }
}