Setting values to a multidimensional array from one class to another; array not initialized?

Question

first time posting. I'm a bit of a C# beginner and am having a bit of trouble setting values to a multi-dimensional array. The array is held in one class and I'm trying to set the values from another class. The problem I can't work out is how to initialize the array variable from the other class? In one class (GRID) I have:

public float[,] values;

then in another class i try to reference the array using a class object (grid) like this:

GRID grid = new GRID();
this.lblFirstVal.Text = "First Value (0,0): " + grid.values[0, 0];

and I get an error on the grid.values[0,0] part of the code: Object reference not set to an instance of an object.

Still a bit new to OO programming so I've probably not understood something properly, but I can't for the life of me work this one out. Thanks in advance for any help!

p.s.w.g · Accepted Answer · 2013-08-17 21:57:04Z

1

Make sure you initialize the values array appropriately, either by using a field initializer:

public float[,] values = new float[1, 1];    // new 1 by 1 array

Or by setting the value of the field in the constructor:

public float[,] values;

public GRID() {
    this.values = new float[1, 1];           // new 1 by 1 array
}

Or you can set the value of the field externally:

GRID grid = new GRID();
grid.values = new float[1, 1];               // new 1 by 1 array
this.lblFirstVal.Text = "First Value (0,0): " + grid.values[0, 0];

Of course, you may want to set the width an height to something other than 1.

edited Aug 17, 2013 at 21:57

answered Aug 17, 2013 at 21:47

p.s.w.g

150k31 gold badges307 silver badges339 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

T_Bacon Over a year ago

Thanks very much, I used the last option and set the value of the field externally. Working properly now!

Collectives™ on Stack Overflow

Setting values to a multidimensional array from one class to another; array not initialized?

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related