/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

/*
  Example5_6.cs illustrates passing parameters by value
*/


// declare the Swapper class
class Swapper
{

  // the Swap() method swaps parameters passed by value
  public void Swap(int x, int y)
  {

    // display the initial values
    System.Console.WriteLine("In Swap(): initial x = " + x +
      ", y = " + y);

    // swap x and y
    int temp = x;
    x = y;
    y = temp;

    // display the final values
    System.Console.WriteLine("In Swap(): final   x = " + x +
      ", y = " + y);
  }

}


public class Example5_6
{

  public static void Main()
  {

    // declare x and y (the variables whose values
    // are to be swapped)
    int x = 2;
    int y = 5;

    // display the initial values
    System.Console.WriteLine("In Main(): initial x = " + x +
      ", y = " + y);

    // create a Swapper object
    Swapper mySwapper = new Swapper();

    // swap the values in x and y
    mySwapper.Swap(x, y);

    // display the final values
    System.Console.WriteLine("In Main(): final   x = " + x +
      ", y = " + y);

  }

}

           
          

   

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

/*
  Example5_7.cs illustrates passing parameters by reference
*/


// declare the Swapper class
class Swapper
{

  // the Swap() method swaps parameters passed by reference
  public void Swap(ref int x, ref int y)
  {

    // display the initial values
    System.Console.WriteLine("In Swap(): initial x = " + x +
      ", y = " + y);

    // swap x and y
    int temp = x;
    x = y;
    y = temp;

    // display the final values
    System.Console.WriteLine("In Swap(): final   x = " + x +
      ", y = " + y);

  }

}


public class Example5_7
{

  public static void Main()
  {

    // declare x and y (the variables whose values
    // are to be swapped)
    int x = 2;
    int y = 5;

    // display the initial values
    System.Console.WriteLine("In Main(): initial x = " + x +
      ", y = " + y);

    // create a Swapper object
    Swapper mySwapper = new Swapper();

    // swap the values, passing a reference to the Swap() method
    mySwapper.Swap(ref x, ref y);

    // display the final values
    System.Console.WriteLine("In Main(): final   x = " + x +
      ", y = " + y);

  }

}

           
          

   

/*
Learning C# 
by Jesse Liberty

Publisher: O'Reilly 
ISBN: 0596003765
*/
 using System;

 namespace ParamsDemo
 {
    public class TesterParamsDemo
    {
       public void Run()
       {
           int a = 5;
           int b = 6;
           int c = 7;
           Console.WriteLine("Calling with three integers");
           DisplayVals(a,b,c);

           Console.WriteLine("
Calling with four integers");
           DisplayVals(5,6,7,8);

           Console.WriteLine("
calling with an array of four integers");
           int [] explicitArray = new int[4] {5,6,7,8};
           DisplayVals(explicitArray);
       }

        // takes a variable number of integers
        public void DisplayVals(params int[] intVals)
        {
            foreach (int i in intVals)
            {
                Console.WriteLine("DisplayVals {0}",i);
            }
        }

       [STAThread]
       static void Main()
       {
          TesterParamsDemo t = new TesterParamsDemo();
          t.Run();
       }
    }
 }

           
          

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Use regular parameter with a params parameter. 
 
using System; 
 
class MyClass { 
  public void showArgs(string msg, params int[] nums) { 
    Console.Write(msg + ": "); 
 
    foreach(int i in nums) 
      Console.Write(i + " "); 
 
    Console.WriteLine(); 
  } 
} 
 
public class ParamsDemo2 { 
  public static void Main() { 
    MyClass ob = new MyClass(); 
 
    ob.showArgs("Here are some integers",  
                1, 2, 3, 4, 5); 
 
    ob.showArgs("Here are two more",  
                17, 20); 
 
  } 
}

           
          

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Demonstrate params.

using System;

class Min {
public int minVal(params int[] nums) {
int m;

if(nums.Length == 0) {
Console.WriteLine(“Error: no arguments.”);
return 0;
}

m = nums[0];
for(int i=1; i < nums.Length; i++) if(nums[i] < m) m = nums[i]; return m; } } public class ParamsDemo { public static void Main() { Min ob = new Min(); int min; int a = 10, b = 20; // call with two values min = ob.minVal(a, b); Console.WriteLine("Minimum is " + min); // call with 3 values min = ob.minVal(a, b, -1); Console.WriteLine("Minimum is " + min); // call with 5 values min = ob.minVal(18, 23, 3, 14, 25); Console.WriteLine("Minimum is " + min); // can call with an int array, too int[] args = { 45, 67, 34, 9, 112, 8 }; min = ob.minVal(args); Console.WriteLine("Minimum is " + min); } } [/csharp]

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Swap two references. 
 
using System; 
 
class RefSwap { 
  int a, b; 
   
  public RefSwap(int i, int j) { 
    a = i; 
    b = j; 
  } 
 
  public void show() { 
    Console.WriteLine("a: {0}, b: {1}", a, b); 
  } 
 
  // This method now changes its arguments. 
  public void swap(ref RefSwap ob1, ref RefSwap ob2) { 
    RefSwap t; 
  
    t = ob1; 
    ob1 = ob2; 
    ob2 = t; 
  } 
} 
 
public class RefSwapDemo { 
  public static void Main() { 
    RefSwap x = new RefSwap(1, 2); 
    RefSwap y = new RefSwap(3, 4); 
 
    Console.Write("x before call: "); 
    x.show(); 
 
    Console.Write("y before call: "); 
    y.show(); 
 
    Console.WriteLine(); 
 
    // exchange the objects to which x and y refer 
    x.swap(ref x, ref y);  
 
    Console.Write("x after call: "); 
    x.show(); 
 
    Console.Write("y after call: "); 
    y.show(); 
 
  } 
} 


           
          

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Use two out parameters.

using System;

class Num {
/* Determine if x and v have a common denominator.
If so, return least and greatest common denominators in
the out parameters. */
public bool isComDenom(int x, int y,
out int least, out int greatest) {
int i;
int max = x < y ? x : y; bool first = true; least = 1; greatest = 1; // find least and treatest common denominators for(i=2; i <= max/2 + 1; i++) { if( ((y%i)==0) & ((x%i)==0) ) { if(first) { least = i; first = false; } greatest = i; } } if(least != 1) return true; else return false; } } public class DemoOut { public static void Main() { Num ob = new Num(); int lcd, gcd; if(ob.isComDenom(231, 105, out lcd, out gcd)) { Console.WriteLine("Lcd of 231 and 105 is " + lcd); Console.WriteLine("Gcd of 231 and 105 is " + gcd); } else Console.WriteLine("No common denominator for 35 and 49."); if(ob.isComDenom(35, 51, out lcd, out gcd)) { Console.WriteLine("Lcd of 35 and 51 " + lcd); Console.WriteLine("Gcd of 35 and 51 is " + gcd); } else Console.WriteLine("No common denominator for 35 and 51."); } } [/csharp]