Geeks With Blogs
Jim Lahman's Blog Fortitude|Endurance|Faith|Teamwork

Last night, I attended the local C# SIG.  I make sure I attend this SIG on a monthly basis.  The topic was on the new features C# 2010.  Here are my notes.

static dynamic type

  • bypass type checking
  • offload until runtime
  • implicit conversion
  • Examples
    • dynamic d = 7; // implicit conversion
    • int i = d;  // Since d is int, we can assign it to an integer
    • d = "Hello world"   // Now, d is a string
    • int i = d;  // this will not work (cannot place a string in int)
  • Can take on type of object, which means that d can call methods from an object such as: 
    • dynamic d = o1.m()
    • but, this means that we can reassign d to another object that happens to have the same method name.  On a personal note, I can see this leading to bad code.  See this example:
      • dynamic d = obj;
      • d.method();
      • dynamic d = obj1;
      • d.method();  
  • This was feature was because of the inclusion of F# and IronRuby in the Microsoft tool kit.
  • yhere was a discussion if datatypes are tied to memory space or method space.  It was decided that datatypes are tied to method space unless they are declared as public.

covariance/contravariant

  • converting specific to generic (string to object)
  • utilize out keyword
  • enable implicit reference conversion for array, delegates, interfaces (generic type argument)
  • These are mostly used for generic interfaces

contravariant

  • converting generic to specific (ex: generic to string)
  • utilize in keyword

optional parameters

  • lead to named parameters
  • public void M(int x, int y=5, int z=7, int ii); // ii is the optional parameter
  • M(1,Z:3);
  • optional parameters after required arguments

COM Interop

  • PIA:.Net assembly generated from COM interface
  • No PIA deployment at runtime
  • Compiler will incorporate necessary features into assembly
  • ByRef implicitly defined

Call Hierarchy

  • enables tp explore all possible execution paths
  • shows 'Calls To'
  • shows 'Call From'
  • from generic to specific

Tuples

  • fixed-size collection of different typed data. 
  • strong typing for each element
  • System.Tuple
  • var BigTuple = Tuple.Create("Value",1,2,3,5.7, "Test",7)
  • var Element1 = BigTuple.Item1;
  • Tuple<string, int> t = new Tuple<string, int>("Hello", 4)
  • string s = t.item1;
  • int i = t.item2;
Posted on Wednesday, July 28, 2010 2:36 PM | Back to top


Comments on this post: Comments from July Cleveland C# Sig

No comments posted yet.
Your comment:
 (will show your gravatar)


Copyright © Jim Lahman | Powered by: GeeksWithBlogs.net