vsbabu.org

C# day 3

• I love object.Parse() method, especially for dates.
• Quite a few C# code samples seem to use object.ToString() liberally. Kasia talked about abuse and overuse of toString in Java.
• Like Java, C# also provides only single inheritance. Python can do multiple inheritance. I favour single inheritance coupled with interfaces though.
• Unlike Java, C# needs a virtual keyword for virtual function. In Java, methods are assumed to be virtual unless specified by final. This might cause some performance enhancement due to less dynamic binding. There is also a sealed keyword!
• I think I like the keyword override. It is better to be explicit.
• C# supports operator overloading. Java doesn't, Python does.
• I like Properties a bit more than usual getX/setX in Java. Python descriptors.
• as and is are useful little operators to compare object types. I've come to love is in Python.
• Like Java, C# also has abstract classes. This is something I miss in Python; though it is possible to prevent instantiation of base classes in Python. Additionally, there is metaclasses in Python, but that is a bit too much for me, most of the time.
• Like Java, C# support interfaces. Python doesn't have an interface keyword, but good folks at Zope Corp has a scarecrow implementation.
• The list (or Collection) classes are there just like in Java. I still can't figure out why these modern languages chose to re-invent the wheel rather than implement something like Python's simple but much more powerful lists, dicts and tuples.
• C# has a concept of attributes. Pretty powerful stuff, but I would've preferred it to be inside the method code immediately after method definition rather than immediately before it.
• Reference data types are always passed by reference. The only way to make sure your object doesn't get modified after you pass it to a method (say, from a third party library) is by creating and passing a clone.

1. Regarding Kasia's comments on string abuse, I'd say C# has a nice debugging solution that can't be done as cleanly in Java. You can easily create a Trace() that take a variable-length list of arguments, checks each for null and handles it nicely.

   Something like this (which will looks junky, since html is disabled -- maybe it would be better to have a limited subset?):

   public static string Trace( object sender, string msg, params Object[] things )
   {
   if( Verbose || Debugging )
   {
   try
   {
   if( sender == null )
   sender = System.AppDomain.CurrentDomain;
   System.Diagnostics.StackFrame frame = new System.Diagnostics.StackTrace().GetFrame(1);
   if(frame.GetMethod().Name == "Trace")
   frame = new System.Diagnostics.StackTrace().GetFrame(2);
   System.Text.StringBuilder text = new System.Text.StringBuilder( sender.GetType().Name );
   text.Append( "." );
   text.Append( frame.GetMethod().Name );
   text.Append( "(): " );

   if( things.Length > 0 )
   for( int i = 0; i ":things[i].ToString() );

   
   text.Append(msg);
   msg = text.ToString();

   System.Diagnostics.Trace.WriteLine( msg );

   if(Logging)
   Log(msg);
   }
   catch
   {
   // can't trace!
   }
   }
   return msg;
   }
   

   Posted by: Matt Gerrans on September 22, 2003 04:48 PM