Question

This is how I am trying to implement my PictureBox arrays:

    PictureBox[] column0 = new PictureBox[6];
    PictureBox[] column1 = new PictureBox[6];
    PictureBox[] column2 = new PictureBox[6];
    PictureBox[] column3 = new PictureBox[6];
    PictureBox[] column4 = new PictureBox[6];
    PictureBox[] column5 = new PictureBox[6];
    PictureBox[] column6 = new PictureBox[6];

    PictureBox[][] columns = 
            new PictureBox[][] 
            { column0, column1, column2, column3, column4, column5, column6 };

When I try to make the array of arrays, I get this error:

A field initializer cannot reference the non-static field method, or property ‘Connect_Four_Server.Server.column0’

and same errors for column1, column2, etc.

How does one declaring an array of arrays correctly in this situation?

Answer 1

There’s nothing wrong with the above declaration per se, but you can’t use it like that if you are declaring fields in a class. As the error states, a field initializer (in your case columns) can’t reference other non static fields (in your case column0, column1…).

There are 2 approaches you can take:

Either don’t declare intermediate fields and do it all in one piece (best unless you actually need direct references to columnX):

PictureBox[][] columns =
        new PictureBox[][] 
        { 
            new PictureBox[6], 
            new PictureBox[6], 
            new PictureBox[6], 
            new PictureBox[6], 
            new PictureBox[6], 
            new PictureBox[6], 
            new PictureBox[6] 
        };

Or put the initialization of columns into the constructor:

PictureBox[] column0 = new PictureBox[6];
PictureBox[] column1 = new PictureBox[6];
PictureBox[] column2 = new PictureBox[6];
PictureBox[] column3 = new PictureBox[6];
PictureBox[] column4 = new PictureBox[6];
PictureBox[] column5 = new PictureBox[6];
PictureBox[] column6 = new PictureBox[6];

PictureBox[][] columns;

public Server()
{
    columns = new PictureBox[][] { column0, column1, column2, column3, column4, column5, column6 };
}