RE: C# Question

Once you know the size, you then have to assign something to your reference,
using the size as the parameters to the constructor.

Currently, you just have an array reference pointing to null, so you'll get
a null pointer exception.

But, you have to have that reference pointing to an array, given to you by
the constructor like so:

myArray = new MyClass[colSize][rowSize];

If you won't know the sizes ahead of time, then you can do one of a few
things, but the most popular solution will be to use a vector datatype
instead of an array datatype.

Arrays do not grow automatically.

Take care,
Sina 

-----Original Message-----
From: programmingblind-bounce@xxxxxxxxxxxxx
[mailto:programmingblind-bounce@xxxxxxxxxxxxx] On Behalf Of Chris Hofstader
Sent: Sunday, March 30, 2008 2:27 PM
To: programmingblind@xxxxxxxxxxxxx
Subject: C# Question

Hi,
 
I have a class which, for purposes of illustration, I'll call MyClass.  I
want to declare a two dimensional array of this class so I can have a set of
rows and columns within.  I don't know the ultimate size of the array so I
declare it with empty brackets.  
 
For instance:
 
MyArray[][] dataTable;  // This compiles without error
 
but, in the code, if I state:
 
dataTable[0][0] = new MyClass();
 
I get an exception about a NULL assignment when the code is executed.
 
I had thought that .Net arrays declared without the "fixed" keyword would
grow dynamically and that the Array type overloaded the brackets to ensure
the sort of exception I'm getting doesn't happen.
 
Obviously, I'm doing something quite wrong but I'm having trouble finding
examples of C# arrays of anything more complex than int or String.
 
Please help.
 
Thanks,
cdh
 
Chris Hofstader
CUNY, BSO, ATG, Odds and Ends
email: cdh@xxxxxxxxxxxxx
Blog: http://www.blindconfidential.blogspot.com
Skype: BlindChristian
phone: 727-896-6393
 
 

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