c# - Keeping Scores in Unity and pass to next scene

Question

After reading and trying many different examples, I am still stuck with this fairly simple problem on getting a score from one level to the next in Unity.

I have a C# script that handles my game logic for a level:

First, I set my level variables:

    public class GameLogic : MonoBehaviour {

public GUIText countText;
public GUIText targetCity;
public GUIText gameOverText;
public GUIText endScoreText;
public GUIText timerText;
public Texture2D bgImage;
private int count;
public GameObject cityPrefab;
List<MyCity> mycities;
public float finalScore; // I Want this value to be available when my next scene loads
private float startTime;

After this, my level code executes fine, until the GameOver condition is met (time is up). Then, this code executes:

    public void GameOver ()
{
    gameOverText.text = "time is up!";
    endScoreText.text = "You have found " + count.ToString() + " cities. Good wrok!";
    Destroy (GameObject.FindWithTag("EmptyCity"));
    Destroy (GameObject.FindWithTag("City"));
    Destroy (GameObject.FindWithTag("TargetCity"));
    finalScore = count; // SO AT THIS STAGE, MY FINAL SCORE IS SET AND READY TO BE PASSED TO THE NEXT SCENE. QUESTION IS HOW?




    StartCoroutine(Wait());

}



IEnumerator Wait() {

    yield return new WaitForSeconds(7);
    Application.LoadLevel (3);
}

So, I end my level with an updated value in public float 'finalScore'. So far so good. Now my problem starts: Level 3 loads and all gameobjects from level 2 are destroyed. In my game, level 3 is a simple Unity scene where I congratulate the player on his performance. I want to have access to that public float finalScore from my previous scene (level2).

I know I have to use Dontdestroyonload somewhere. But I don't know how. How and where do I create a GameObject that has the public float 'finalScore' in it? How do I call that GameObject in my new level so that I can do something like this in my new level:

    public GUIText ContratsOnScore;

    void SetContratsText() {

    CongratsOnScore = "Congratulations, you scored" + (finalScoreFloatValue from Previous level).ToString(); 

Answer 1

The DontDestroyOnLoad method is callable on an object, not on a single variable. It represents the best possible approach for a value of that kind, that needs to be "exported" from your actual scene.

However, you can also use PlayerPrefs. They are intended for informations at a "higher" level of persistency, like flags for unlocked levels, final scores for a ranking system, or attributes of a customizable character. That's why the DontDestroyOnLoad way is better suited (for your "temporary" score), but you can use this one also. Basically, PlayerPrefs are information stored in the registry of your operative system.

Before exiting from the actual scene, save the score this way:

PlayerPrefs.SetInt("Player Score", finalScore);

And, when next scene starts, initialize score's variable by retrieving that information:

finalScore = PlayerPrefs.GetInt("Player Score");

(here a similar post)