How to manage save/load of hundreds of variables

Question

I am making a RPG in Unity. Still quite new so I followed their tutorial on creating save/load functionality.

In this tutorial they use 2 variables, and for that it works great. But I want to create a large game, with sandboxing. Which means Ill need to save the position of everything in my world, on top of that I want a lot of player stats, unlockables, quests, npc progress, and much more.

So far I have a working implementation for saving/loading my players initial stats, and that alone has turned in to a lot:

DataManager

public class DataManager : MonoBehaviour {

    private string saveLocation = "/data.dat";

    public static DataManager manager;

    //PLAYER
    public int maxHealth;
    public int currentHealth;
    public int currentLevel;
    public int currentExp;
    public int [] toLevelUp;

    void Awake(){
        if (manager == null) {
            DontDestroyOnLoad (gameObject);
            manager = this;
        } else if (manager != this) {
            Destroy (gameObject);
        }
    }


    public void Save(){
        Debug.Log ("Saving");
        BinaryFormatter bf = new BinaryFormatter ();
        FileStream file = File.Create (Application.persistentDataPath + saveLocation);

        PlayerData playerData = new PlayerData (maxHealth, currentHealth, currentLevel, currentExp, toLevelUp);

        bf.Serialize (file, playerData);
        file.Close ();
    }

    public void Load(){
        Debug.Log ("Loading");
        if (File.Exists (Application.persistentDataPath + saveLocation)) {
            BinaryFormatter bf = new BinaryFormatter ();
            FileStream file = File.Open (Application.persistentDataPath + saveLocation, FileMode.Open);

            PlayerData playerData = (PlayerData)bf.Deserialize (file);
            file.Close ();

            maxHealth = playerData.maxHealth;
            currentHealth = playerData.currentHealth;
            currentLevel = playerData.currentLevel;
            currentExp = playerData.currentExp;
            toLevelUp = playerData.toLevelUp;
        }
    }
}

PlayerData

[System.Serializable]
public class PlayerData {

    public int maxHealth;
    public int currentHealth;
    public int currentLevel;
    public int currentExp;
    public int [] toLevelUp;

    public PlayerData(int maxHealth, int currentHealth, int currentLevel, int currentExp, int [] toLevelUp){
        this.maxHealth = maxHealth;
        this.currentHealth = currentHealth;
        this.currentLevel = currentLevel;
        this.currentExp = currentExp;
        this.toLevelUp = toLevelUp;
    }

}

This does not feel very scaleable at all. Someone with experience implementing save/load for a lot of variables with any advice/code samples? There must be some better way?

EDIT:

New DataManager:

public class DataManager : MonoBehaviour {

private string saveLocation = "/data.dat";

public static DataManager manager;

//PLAYER
public PlayerData playerData = new PlayerData ();

void Awake(){
    if (manager == null) {
        DontDestroyOnLoad (gameObject);
        manager = this;
    } else if (manager != this) {
        Destroy (gameObject);
    }

}


public void Save(){
    Debug.Log ("Saving");
    BinaryFormatter bf = new BinaryFormatter ();
    FileStream file = File.Create (Application.persistentDataPath + saveLocation);

    bf.Serialize (file, playerData);
    file.Close ();
}

public void Load(){
    Debug.Log ("Loading");
    if (File.Exists (Application.persistentDataPath + saveLocation)) {
        BinaryFormatter bf = new BinaryFormatter ();
        FileStream file = File.Open (Application.persistentDataPath + saveLocation, FileMode.Open);

        PlayerData pd = (PlayerData)bf.Deserialize (file);
        file.Close ();

        playerData = pd;
    }
}

}

Answer 1

You don't have to create new PlayerData each time you want to save it. You don't have to copy it like you did in the constructor. Create an instance of PlayerData then use it in your game. That's that. Remove those local variables because they are already in the PlayerData class.

Don't do this:

[System.Serializable]
public class PlayerData
{

    public int maxHealth;
    public int currentHealth;
    public int currentLevel;
    public int currentExp;
    public int[] toLevelUp;
}

//Why Why would you need these again?
public int maxHealth;
public int currentHealth;
public int currentLevel;
public int currentExp;
public int[] toLevelUp;

private string saveLocation = "/data.dat";

//PLAYER
public PlayerData playerData = new PlayerData();

public void Save()
{
    if (File.Exists(Application.persistentDataPath + saveLocation))
    {
        BinaryFormatter bf = new BinaryFormatter();
        FileStream file = File.Open(Application.persistentDataPath + saveLocation, FileMode.Open);

        PlayerData playerData = (PlayerData)bf.Deserialize(file);
        file.Close();

        //Whyyyyyyyyyyyy Don't do this
        maxHealth = playerData.maxHealth;
        currentHealth = playerData.currentHealth;
        currentLevel = playerData.currentLevel;
        currentExp = playerData.currentExp;
        toLevelUp = playerData.toLevelUp;
    }
}

Notice how you redefined the maxHealth, currentHealth, currentLevel, currentExp and toLevelUp variables again. Not necessary at-all.

Do this:

[System.Serializable]
public class PlayerData
{

    public int maxHealth;
    public int currentHealth;
    public int currentLevel;
    public int currentExp;
    public int[] toLevelUp;
}

string saveLocation = "/data.dat";

//Make the PlayerData data part of your game
PlayerData playerData;

void Start()
{

    playerData = new PlayerData();
    playerData.maxHealth = 100;
    playerData.currentLevel = 1;
    playerData.currentHealth = 50;
}

public void Save(PlayerData pData)
{
    UnityEngine.Debug.Log("Saving");
    BinaryFormatter bf = new BinaryFormatter();
    FileStream file = File.Create(Application.persistentDataPath + saveLocation);
    bf.Serialize(file, pData);
    file.Close();
}

When you want to save, just call Save(playerData);.

Notice how there is no need to copy the data or do PlayerData playerData = new PlayerData (maxHealth, currentHealth, currentLevel, currentExp, toLevelUp);. Just save the instance you are already using in your game.

---

Finally, with DataSaver, you can do this in one line DataSaver.saveData(playerData, "players");