• A C# program consists of one or more files
• Each file contains zero or more namespaces
• Each namespace can contain:
  • Classes
  • Interfaces
  • Structs
  • Enums
  • Delegates
  • Nested namespaces

Compiling a program from the command line

• Open a Visual Studio Command Prompt, or,
• Open a command prompt and type vsvars32.bat (to put the Visual C# toolset on the path)
• type csc prog.cs

The Main method:

static void Main( )
static int Main( )
static void Main( string[] args )
static int Main( string[] args )
{
if( args.Length == 0 ) {
}
}

- The Main method is declared inside a class or a struct
- Main must be static
- Main should not be public
- The containing class or struct doesn't need to be static
- args[0] is the first parameter, not the program name.

- A program can have more than one class containing a Main method. However, only one can be chosen as the entry point ( /main compiler option)

long aliases Int64