/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/

// 20 - EnumerationsThe System.Enum Type
// copyright 2000 Eric Gunnerson
using System;

enum Color
{
    red,
    green,
    yellow
}

public class TheSystemEnumType2
{
    public static void Main()
    {
        Color c = Color.red;
        
        // enum values and names
        foreach (int i in Enum.GetValues(c.GetType()))
        {
            Console.WriteLine("Value: {0} ({1})", i, Enum.GetName(c.GetType(), i));
        }
        
        // or just the names
        foreach (string s in Enum.GetNames(c.GetType()))
        {
            Console.WriteLine("Name: {0}", s);
        }
        
        // enum value from a string, ignore case
        c = (Color) Enum.Parse(typeof(Color), "Red", true);
        Console.WriteLine("string value is: {0}", c);
        
        // see if a specific value is a defined enum member
        bool defined = Enum.IsDefined(typeof(Color), 5);
        Console.WriteLine("5 is a defined value for Color: {0}", defined);    
    }
}
           
         
    
     

   
  
using System;

enum Color
{
    red,
    green,
    yellow
}

public class TheSystemEnumType1
{
    public static void Main()
    {
        Color c = Color.red;
        
        Console.WriteLine("c is {0}", c);
    }
}
           
         
    
     

   
  

enum Values
{
    A = 1,
    B = 5,
    C = 3,
    D = 42
}

public class EnumerationsConversions
{
    public static void Main()
    {
        Values v = (Values) 2;
        int ival = (int) v;
    }
}
           
         
    
     

   
  
using System;

[Flags]
public enum BitValues: uint
{
    NoBits = 0,
    Bit1 = 0x00000001,
    Bit2 = 0x00000002,
    Bit3 = 0x00000004,
    Bit4 = 0x00000008,
    Bit5 = 0x00000010,
    AllBits = 0xFFFFFFFF
}

public class BitFlagEnums
{
    public static void Member(BitValues value)
    {
        // do some processing here
    }
    public static void Main()
    {
        Member(BitValues.Bit1 | BitValues.Bit2);
    }
}
           
         
    
     

   
  
/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/
// 19 - Indexers and EnumeratorsEnumerators and Foreach
// copyright 2000 Eric Gunnerson
using System;
using System.Collections;

// Note: This class is not thread-safe
class IntList: IEnumerable
{
    int[] values = new int[10];
    int allocated = 10;
    int count = 0;
    int revision = 0;
    
    public void Add(int value)
    {
        // reallocate if necessary
        if (count + 1 == allocated)
        {
            int[] newValues = new int[allocated * 2];
            for (int index = 0; index < count; index++)
            {
                newValues&#91;index&#93; = values&#91;index&#93;;
            }
            allocated *= 2;
        }        
        values&#91;count&#93; = value;
        count++;
        revision++;
    }
    
    public int Count
    {
        get
        {
            return(count);
        }
    }
    
    void CheckIndex(int index)
    {
        if (index >= count)
        throw new ArgumentOutOfRangeException("Index value out of range");
    }
    
    public int this[int index]
    {
        get
        {
            CheckIndex(index);
            return(values[index]);
        }
        set
        {
            CheckIndex(index);
            values[index] = value;
            revision++;
        }
    }
    
    public IEnumerator GetEnumerator()
    {
        return(new IntListEnumerator(this));
    }
    
    internal int Revision
    {
        get
        {
            return(revision);
        }
    }
}

class IntListEnumerator: IEnumerator
{
    IntList    intList;
    int revision;
    int index;
    
    internal IntListEnumerator(IntList intList)
    {
        this.intList = intList;
        Reset();
    }
    
    public bool MoveNext()
    {
        index++;
        if (index >= intList.Count)
        return(false);
        else
        return(true);
    }
    
    public object Current
    {
        get
        {
            if (revision != intList.Revision)
            throw new InvalidOperationException("Collection modified while enumerating.");
            return(intList[index]);
        }
    }
    
    public void Reset()
    {
        index = -1;
        revision = intList.Revision;
    }
}

public class EnumeratorsandForeach {
    public static void Main()
    {
        IntList list = new IntList();
        
        list.Add(1);
        list.Add(55);
        list.Add(43);
        
        foreach (int value in list)
        {
            Console.WriteLine("Value = {0}", value);
        }
        
        foreach (int value in list)
        {
            Console.WriteLine("Value = {0}", value);
            list.Add(124);
        }
    }
}

           
         
    
     

   
  
/*
C#: The Complete Reference 
by Herbert Schildt 

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

// Demonstrate IDictionaryEnumerator. 
 
using System; 
using System.Collections; 
 
public class IDicEnumDemo { 
  public static void Main() { 
    // Create a hash table. 
    Hashtable ht = new Hashtable(); 
     
    // Add elements to the table 
    ht.Add("Tom", "555-3456"); 
    ht.Add("Mary", "555-9876"); 
    ht.Add("Todd", "555-3452"); 
    ht.Add("Ken", "555-7756"); 
 
    // Demonstrate enumerator 
    IDictionaryEnumerator etr = ht.GetEnumerator(); 
    Console.WriteLine("Display info using through Entry."); 
    while(etr.MoveNext())  
     Console.WriteLine(etr.Entry.Key + ": " +  
                       etr.Entry.Value); 
 
    Console.WriteLine(); 
 
    Console.WriteLine("Display info using Key and Value directly."); 
    etr.Reset(); 
    while(etr.MoveNext())  
     Console.WriteLine(etr.Key + ": " +  
                       etr.Value); 
     
  } 
}


           
         
    
     

/*
C#: The Complete Reference
by Herbert Schildt

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

// Demonstrate an enumerator.

using System;
using System.Collections;

public class EnumeratorDemo {
public static void Main() {
ArrayList list = new ArrayList(1);

for(int i=0; i < 10; i++) list.Add(i); // Use enumerator to access list. IEnumerator etr = list.GetEnumerator(); while(etr.MoveNext()) Console.Write(etr.Current + " "); Console.WriteLine(); // Re-enumerate the list. etr.Reset(); while(etr.MoveNext()) Console.Write(etr.Current + " "); Console.WriteLine(); } } [/csharp]