Csharp/C Sharp/Language Basics/Function Definition

Catch StackOverflowException for recursive function

<source lang="csharp">

using System;

class MainClass {

   public static void Main()
   {
       try
       {
           Recursive();
       }
       catch(StackOverflowException)
       {
           Console.WriteLine("The CLR is out of stack space.");
       }
   }
  
   public static void Recursive()
   {
       Recursive();
   }

}

      </source>

Define function

<source lang="csharp"> /* Learning C# by Jesse Liberty Publisher: O"Reilly ISBN: 0596003765

• /

using System;

public class Functions

{
    static void Main()
    {
        Console.WriteLine("In Main! Calling SomeMethod()...");
        SomeMethod();
        Console.WriteLine("Back in Main().");
    }
    static void SomeMethod()
    {
        Console.WriteLine("Greetings from SomeMethod!");
    }
}
          
      </source>

Recursive Factorial method.

<source lang="csharp">

using System; public class FactorialTest {

  public static void Main( string[] args )
  {
     for ( long counter = 0; counter <= 10; counter++ )
        Console.WriteLine( "{0}! = {1}", counter, Factorial( counter ) );
  } 
  public static long Factorial( long number )
  {
     if ( number <= 1 )
        return 1;
     else
        return number * Factorial( number - 1 );
  } 

}

             </source>

Recursive function in action

<source lang="csharp"> using System; public class FactorialTest {

  public static void Main( string[] args )
  {
     for ( long counter = 0; counter <= 10; counter++ )
        Console.WriteLine( "{0}! = {1}",
           counter, Factorial( counter ) );
  }
  public static long Factorial( long number )
  {
     if ( number <= 1 )
        return 1;
     else
        return number * Factorial( number - 1 );
  }

}

      </source>

Recursive sum method

<source lang="csharp"> public class SumPrices {

 public static double Sum(double[] p, int start, int end) {
   if (start < end)
      return p[start] + Sum(p,start+1,end);
   else return 0;
 }
 public static void Main() {
   double[] prices = {1.3, 13.68, 314.919, 82.827, 363.949};
   System.Console.WriteLine("The sum is {0:C}", Sum(prices,0,prices.Length));
 }

}

      </source>

Use a recursive method, travel, to journey from start to finish

<source lang="csharp"> using System; public class Journey {

 private static String indent = "";
 
 public static void TakeOneStep(int step) {
   Console.WriteLine("{0}Taking step {1}", indent, step);
 }
 
 public static void Move(int start, int finish) {
   string oldIndent = indent;
   Console.WriteLine("{0}Starting move from {1} to {2}", indent, start, finish);
   if (start < finish) {
     TakeOneStep(start);
     indent += "   "; 
     Move(start+1, finish);
     indent = oldIndent;
   }
   Console.WriteLine("{0}Finishing move from {1} to {2}",indent, start, finish);
 }
 public static void Main(String [] args) {
   Move(1, 10);
 }

}

      </source>