Csharp/C Sharp/Language Basics/While

a do...while loop

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
  Example4_10.cs illustrates the use of
  a do...while loop
*/
public class Example4_10
{
  public static void Main()
  {
    int counter = 1;
    do
    {
      System.Console.WriteLine("counter = " + counter);
      counter--;
    }
    while (counter > 1);
  }
}

Compute integer powers of 2

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Compute integer powers of 2. 
 
using System; 
 
public class Power {   
  public static void Main() { 
    int e; 
    int result; 
 
    for(int i=0; i < 10; i++) { 
      result = 1; 
      e = i; 
 
      while(e > 0) { 
        result *= 2; 
        e--; 
      } 
 
      Console.WriteLine("2 to the " + i +  
                         " power is " + result);        
    } 
  }   
}

Compute the order of magnitude of an integer

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Compute the order of magnitude of an integer 
 
using System; 
 
public class WhileDemo {   
  public static void Main() { 
    int num; 
    int mag; 
 
    num = 435679; 
    mag = 0; 
 
    Console.WriteLine("Number: " + num); 
 
    while(num > 0) { 
      mag++; 
      num = num / 10; 
    }; 
 
    Console.WriteLine("Magnitude: " + mag); 
  }   
}

Continue in while

/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 */
using System;
namespace Client.Chapter_4___Program_Control
{
  public class MyMainClass11
  {
    static void Main(string[] args)
    {
      WhileContinue();
      WhileBreak();
      WhileGoto();
    }
    static void WhileContinue()
    {
      int a = 0;
      
      while(a < 10)
      {
        a++;
        if (a == 5)
        {
          a++;
          continue;
        }
      }
    }
    static void WhileBreak()
    {
      int a = 0;
      while (a < 10)
      {
        a++;
        if (a == 5)
          break;
      }
      a++;
    }
    static void WhileGoto()
    {
      int a = 0;
      while (a < 10)
      {
        if (a == 5)
          goto cleanup;
      }
    cleanup :
      Console.WriteLine(a);
    }
  }
}

Display the digits of an integer in reverse order

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Display the digits of an integer in reverse order. 
 
using System; 
 
public class DoWhileDemo {   
  public static void Main() { 
    int num; 
    int nextdigit; 
 
    num = 198; 
 
    Console.WriteLine("Number: " + num); 
 
    Console.Write("Number in reverse order: "); 
 
    do { 
      nextdigit = num % 10; 
      Console.Write(nextdigit); 
      num = num / 10; 
    } while(num > 0); 
 
    Console.WriteLine(); 
  }   
}

Do While Tester

/*
Learning C# 
by Jesse Liberty
Publisher: O"Reilly 
ISBN: 0596003765
*/
 using System;
 public class DoWhileTester
 {
     public static void Main()
     {
         int counterVariable = 11;
         // display the message and then test that the value is
         // less than 10
         do
         {
             Console.WriteLine("counterVariable: {0}",counterVariable);
             counterVariable++;
         } while (counterVariable < 10);
     }
 }

Simplest do while

/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 */
using System;
namespace Client.Chapter_4___Program_Control
{
  public class DoWhile
  {
    static void Main(string[] args)
    {
      int a = 0;
      do
      {
        a++;
        Console.WriteLine(a);
      } while (a < 10);
    }
  }
}

Simplest while

/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 */
using System;
namespace Client.Chapter_4___Program_Control
{
  public class Whiles
  {
    static void Main(string[] args)
    {
      int a = 0;
      
      while(a > 10)
      {
        a++;
        Console.WriteLine(a);
      }
    }
  }
}

Using break to exit a do-while loop

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Using break to exit a do-while loop.   
 
using System; 
 
public class BreakDemo2 {  
  public static void Main() {  
    int i; 
 
    i = -10;     
    do { 
      if(i > 0) break; 
      Console.Write(i + " "); 
      i++; 
    } while(i <= 10); 
  
    Console.WriteLine("Done");  
  }  
}

while loop to calculate and display the Fibonacci numbers less than 50

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
  Example4_9.cs illustrates the use of
  a while loop to calculate and display
  the Fibonacci numbers less than 50
*/
public class Example4_9
{
  public static void Main()
  {
    // initialize the first two numbers in the sequence
    int oldNumber = 1;
    int currentNumber = 1;
    int nextNumber;
    System.Console.Write(currentNumber + " ");
    while (currentNumber < 50)
    {
      System.Console.Write(currentNumber + " ");
      // calculate the next number by adding the
      // current number to the old number
      nextNumber = currentNumber + oldNumber;
      oldNumber = currentNumber;
      currentNumber = nextNumber;
    }
  }
}

While loop to display 1 to 5

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy
Publisher: Sybex;
ISBN: 0782129110
*/
/*
  Example4_8.cs illustrates the use of
  a while loop to display 1 to 5
*/
public class Example4_8
{
  public static void Main()
  {
    int counter = 1;
    while (counter <= 5)
    {
      System.Console.WriteLine("counter = " + counter);
      counter++;
    }
  }
}

While Signal

/*
Learning C# 
by Jesse Liberty
Publisher: O"Reilly 
ISBN: 0596003765
*/
 using System;
 public class WhileSignalTester
 {
     public static int Main()
     {
         string signal = "0";      // initialize to neutral
         while (signal != "X")      // X indicates stop
         {
             Console.Write("Enter a signal. X = stop. A = Abort: ");
             signal = Console.ReadLine();
             // do some work here, no matter what signal you
             // receive
             Console.WriteLine("Received: {0}", signal);
             if (signal == "A")
             {
                 // faulty - abort signal processing
                 // Log the problem and abort.
                 Console.WriteLine("Fault! Abort\n");
                 break;
             }
             if (signal == "0")
             {
                 // normal traffic condition
                 // log and continue on
                 Console.WriteLine("All is well.\n");
                 continue;
             }
             // Problem. Take action and then log the problem
             // and then continue on
             Console.WriteLine("{0} -- raise alarm!\n",
                 signal);
         }
         return 0;
     }
 }

While Tester

/*
Learning C# 
by Jesse Liberty
Publisher: O"Reilly 
ISBN: 0596003765
*/
 using System;
 public class WhileTester
 {
     public static void Main()
     {
         int counterVariable = 0;
         // while the counter variable is less than 10
         // print out its value
         while (counterVariable < 10)
         {
             Console.WriteLine("counterVariable: {0}",counterVariable);
             counterVariable++;
         }
     }
 }

While true test

/*
Learning C# 
by Jesse Liberty
Publisher: O"Reilly 
ISBN: 0596003765
*/
 using System;
 public class WhileTrueTester
 {
     public static void Main()
     {
         int counterVariable = 0;  // initialization
         while (true)
         {
             Console.WriteLine(
                 "counter: {0} ", counterVariable++); // increment
             if (counterVariable > 10) // test
                 break;
         }
     }
 }