C# Programming Tutorial ( Part 2 )

As mentioned, the class is C#’s basic unit of encapsulation. Example is the name of the class. The class definition begins with the opening curly brace ({) and ends with the closing curly brace (}). The elements between the two braces are members of the class.
The next line of code is shown here:
static void Main() {
This line begins the Main( ) method. As mentioned earlier, in C#, a subroutine is called a method. As the comment preceding it suggests, this is the line at which the program will begin executing. All C# applications begin execution by calling Main( ).
The line begins with the keyword static. A method that is modified by static can be called before an object of its class has been created. This is necessary because Main( ) is called at program startup. The keyword void indicates that Main( ) does not return a value.
The next line of code is shown here. Notice that it occurs inside Main( ).
Console.WriteLine(“A simple C# program.”);

This line outputs the string “A simple C# program.” followed by a new line on the screen. Output is actually accomplished by the built-in method WriteLine( ).

Second program
using System;
class Example2 {
      static void Main() {
                         int    x; // this declares a variable
                         int    y; // this declares another variable
                         x = 100; // this assigns 100 to x
                          Console.WriteLine(“x contains ” + x);
                          y = x / 2;
                          Console.Write(“y contains x / 2: “);
                          Console.WriteLine(y);
                       }
                 }

Another example
                   using System;
                  class Example3 {
                    static void Main() {
                           int     ivar; // this declares an int variable
                           double dvar; // this declares a floating-point variable
                           ivar = 100; // assign ivar the value 100
                          dvar = 100.0; // assign dvar the value 100.0
                          Console.WriteLine(“Original value of ivar: ” + ivar);
                          Console.WriteLine(“Original value of dvar: ” + dvar);
                           Console.WriteLine(); // print a blank line
                          // Now, divide both by 3.
                          ivar = ivar / 3;
                          dvar = dvar / 3.0;
                          Console.WriteLine(“ivar after division: ” + ivar);
                          Console.WriteLine(“dvar after division: ” + dvar);
                        }
                       }