Access variable from a different scene in Unity

Question

I am fairly new to Unity and C# and am having some trouble. I am designing a 2d game, which has multiple levels. Each level contains a LevelManager which stores whether the leve

Answer 1

You can create a ScoreManager script to store scores of each level using PlayerPrefs and attach this script to a GameObject in the first scene.

public class ScoreManager: MonoBehavior {

    public static ScoreManager Instance;
    const string LEVEL_KEY = "SCORE_";
    const string MAX_LEVEL_KEY = "MAX_LEVEL";

    public static int MAX_LEVEL {
        get { return PlayerPrefs.GetInt(MAX_LEVEL_KEY, 1); }
        set {
            if(value > MAX_LEVEL) {
                PlayerPrefs.SetInt(MAX_LEVEL_KEY, value);
            }
        }
    }

    void Awake() {
        if(Instance != null) {
            Destroy(this.gameObject);
            return;
        }
        Instance = this;
        DontDestroyOnLoad(this);
    }

    public void SaveScore(int level, float score) {
        PlayerPrefs.SetFloat(LEVEL_KEY + level, score);
        MAX_LEVEL = level;
    }

    public float GetScore(int level) {
        return PlayerPrefs.GetFloat(LEVEL_KEY + level, 0);
    }

    public bool IsLevelUnlocked(int level) {
        // You can write your own level-unlock logic here.
        return level <= MAX_LEVEL;
    }
    ...
}

Then you can just call its functions and properties from other scripts.

    ...
    public void GameOver() {
        ScoreManager.Instance.SaveScore(level, score);
    }
    ...

Having all LevelManger scripts with DontDestroyOnLoad will cause a memory leak and sometimes it will affect the game performance.