C# Keywords

The descending keyword (as in orderby ... descending) is not listed above.


CS Team: Both ascending gnad descending have been added in later versions of the documentation. Thanks.

There's actually a bunch of keywords missing!

As mentioned before, there are add and remove, and, of coure, descending and (!) ascending!

In addition to this, I miss the context-based alias-Keyword (as in extern alias).

Then, if I may ask, why don't you document the __makeref, __reftype, __refvalue und __arglist keywords?

And last but not least, though they are not really "keywords", I think that attribute path specifiers would fit here (assembly, module, method etc.)

More about undocumented keywords __makeref, __reftype, __refvalue and __arglist http://www.eggheadcafe.com/articles/20030114.asp .

__makeref

Creates typed reference from a variable.

int i = 1;
TypedReference tr = __makeref(i);

__reftype

Extracts original type of the variable represented by typed reference.

int i = 1;
TypedReference tr = __makeref(i);
Type t = __reftype(tr);

__refvalue

Extracts original value from typed reference.

int i = 1;
TypedReference tr = __makeref(i);
int j = __refvalue(tr, int);

__arglist

Used to work with argument lists (arglists) on methods. Arglist is very similar to params keyword but it is more low-level. While params relies mainly on compiler, arglist has specific support in CIL.
The __arglist keyword can be used to specify method with variable argument list, to pass arguments to such method and to access arguments inside the method.

void AcceptsArguments(__arglist){
    ArgIterator ai = new ArgIterator(__arglist);
    List<object> list = new List<object>();
    while(ai.GetRemainingCount() > 0){
        TypedReference tr = ai.GetNextArg();
        list.Add(TypedReference.ToObject(tr));
    }
}

Usage:

int a = 3;
string b = "3";
char c = '3';
AcceptsArguments(__arglist(a,b,c));

CS Team: What counts as a keyword is defined in the C# Language Specification (http://www.microsoft.com/downloads/details.aspx?FamilyID=dfbf523c-f98c-4804-afbd-459e846b268e&displaylang=en#filelist). Keywords add, remove, ascending, descending, extern, and alias have already been added to later versions of the documentation (http://msdn.microsoft.com/en-us/library/x53a06bb.aspx). Thanks.

(add and remove actually are listed above. It's under "Contextual Keywords")

The add and remove accessor methods (similar to the get and set for a property) are not included in the list above.

These allow you to intercept the calls when others wire up to your events in much the same way as get/set allows you to intercept calls to a property.

Below is some sample code that shows the accessor functions.

public event EventHandler OnClick
{
   add {
      Debug.WriteLine("add called");
      Click += value;
   }
   remove {
      Debug.WriteLine("remove called");
      Click -= value;
   }
}

using System;

class Myclass
{
static void Main()
{
//int[] iPages = { 5,345345 };
//Console.WriteLine(iPages.ToString().Length); => This will output 14

//string[] iPages = { "5","adf","345345" };
//Console.WriteLine(iPages.ToString().Length); => This will output 15
}

}

I'm diving with C# data types, can someone please explain why the results are 14, 15 always?

Reply: If you view the iPages.ToString() you will get something like "System.String[]" Or "System.Int32[]" it doesn't actually print what is contained in the array

Comment:

int intLength = "System.Int32[]".Length;
Assert.IsTrue(intLength==14);