CS0120 occurs (functions) Unity - unity3d

Question

public int[,] position = new int[8, 8];
Figure pawn1 = new Figure();
void Start()
{
pawn1.Create("pawn", 1, new Vector2Int(1, 2));
}
void Update()
{
}
[System.Serializable]
public class Figure
{
public int id;
public void Create(string nameEntered, int IdEntered, Vector2Int positionEntered)
{
position[positionEntered.x, positionEntered.y] = IdEntered;
//CS0120 occurs here
}
}
Getting this error and dont know how to fix it
Is there anyone who´s able to help?
Any kinda help is appreciated

Answer 1

CS0120 means
An object reference is required for the nonstatic field, method, or property 'member'
The reference to
public int[,] position = new int[8, 8];
is non-static or instanced since it doesn't use the keyword static. That means the only way to access it is over the reference of the instance of the outer class.
The solution depends on what you want to do with it:
If you want it non-static so that it is not "shared" between all instances of the outer class a solution could be to pass on your outer classe's instance reference like
private void Start()
{
pawn1.Create("pawn", 1, new Vector2Int(1, 2), this);
}
And in Figure expect according value (replace <OuterType> by the outer classes actual name)
[System.Serializable]
public class Figure
{
public int id;
public void Create(string nameEntered, int IdEntered, Vector2Int positionEntered, <OuterType> reference)
{
reference.position[positionEntered.x, positionEntered.y] = IdEntered;
}
}
Otherwise you can make it static so it is "shared" between all instances of the outer class:
public static int[,] position;
Hint1
If that is all your Create method is supposed to do why not setting the value in the outer class itself?
private void Start()
{
position[1,2] = 1;
// Rather pass on the value in this direction if Figure needs it
pawn1 = new Figure("pawn", position[1,2], /*...*/);
}
Than there is no need to pass position etc on to the Figure instance and than get the value written back (unless there is happening more you didn't show).
Hint2
Instead of create a new Figure in
Figure pawn1 = new Figure();
and than later use its method Create to setup a value you should probably rather use the constructor e.g.:
[System.Serializable]
public class Figure
{
public int id;
public Figure(string nameEntered, int IdEntered, Vector2Int positionEntered, <OuterType> reference)
{
reference.position[positionEntered.x, positionEntered.y] = IdEntered;
}
}
and use it like e.g.
Figure pawn1;
private void Start()
{
pawn1 = new Figure("pawn", 1, new Vector2Int(1, 2), this);
}
Hint3
The usage of Start and Update let's conclude that you are very probably using a MonoBehaviour.
To avoid confusion with the transform.position I'ld recommend to name your field maybe better Positions.
Hint4
So far you are not using any of the Vector2Int's functionality but use it only to get the two int values.
In case you are not doing anything else with positionEntered it would be less overhead to instead of passing on a new Vector2Int only to get two int values simply pass on the int values themselves
pawn1.Create("pawn", 1, 1, 2, this);
and
public void Create(string nameEntered, int IdEntered, int x, int y, <OuterType> reference)
{
reference.position[x, y] = IdEntered;
}
Hint5
In general if you are using MonoBehaviour components but you are not using one of Start or Update etc remove them entirely from your class because Unity calls them as soon as they exist which causes unnecesary overhead.