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ListDictionary.Count Property

Gets the number of key/value pairs contained in the ListDictionary.

Namespace: System.Collections.Specialized
Assembly: System (in system.dll)

public int Count { get; }
/** @property */
public final int get_Count ()

public final function get Count () : int

Not applicable.

Property Value

The number of key/value pairs contained in the ListDictionary.

Retrieving the value of this property is an O(1) operation.

The following code example enumerates the elements of a ListDictionary.

using System;
using System.Collections;
using System.Collections.Specialized;

public class SamplesListDictionary  {

   public static void Main()  {

      // Creates and initializes a new ListDictionary.
      ListDictionary myCol = new ListDictionary();
      myCol.Add( "Braeburn Apples", "1.49" );
      myCol.Add( "Fuji Apples", "1.29" );
      myCol.Add( "Gala Apples", "1.49" );
      myCol.Add( "Golden Delicious Apples", "1.29" );
      myCol.Add( "Granny Smith Apples", "0.89" );
      myCol.Add( "Red Delicious Apples", "0.99" );

      // Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine( "Displays the elements using foreach:" );
      PrintKeysAndValues1( myCol );

      // Display the contents of the collection using the enumerator.
      Console.WriteLine( "Displays the elements using the IDictionaryEnumerator:" );
      PrintKeysAndValues2( myCol );

      // Display the contents of the collection using the Keys, Values, Count, and Item properties.
      Console.WriteLine( "Displays the elements using the Keys, Values, Count, and Item properties:" );
      PrintKeysAndValues3( myCol );

   }

   // Uses the foreach statement which hides the complexity of the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues1( IDictionary myCol )  {
      Console.WriteLine( "   KEY                       VALUE" );
      foreach ( DictionaryEntry de in myCol )
         Console.WriteLine( "   {0,-25} {1}", de.Key, de.Value );
      Console.WriteLine();
   }

   // Uses the enumerator. 
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintKeysAndValues2( IDictionary myCol )  {
      IDictionaryEnumerator myEnumerator = myCol.GetEnumerator();
      Console.WriteLine( "   KEY                       VALUE" );
      while ( myEnumerator.MoveNext() )
         Console.WriteLine( "   {0,-25} {1}", myEnumerator.Key, myEnumerator.Value );
      Console.WriteLine();
   }

   // Uses the Keys, Values, Count, and Item properties.
   public static void PrintKeysAndValues3( ListDictionary myCol )  {
      String[] myKeys = new String[myCol.Count];
      myCol.Keys.CopyTo( myKeys, 0 );

      Console.WriteLine( "   INDEX KEY                       VALUE" );
      for ( int i = 0; i < myCol.Count; i++ )
         Console.WriteLine( "   {0,-5} {1,-25} {2}", i, myKeys[i], myCol[myKeys[i]] );
      Console.WriteLine();
   }

}

/*
This code produces the following output.

Displays the elements using foreach:
   KEY                       VALUE
   Braeburn Apples           1.49
   Fuji Apples               1.29
   Gala Apples               1.49
   Golden Delicious Apples   1.29
   Granny Smith Apples       0.89
   Red Delicious Apples      0.99

Displays the elements using the IDictionaryEnumerator:
   KEY                       VALUE
   Braeburn Apples           1.49
   Fuji Apples               1.29
   Gala Apples               1.49
   Golden Delicious Apples   1.29
   Granny Smith Apples       0.89
   Red Delicious Apples      0.99

Displays the elements using the Keys, Values, Count, and Item properties:
   INDEX KEY                       VALUE
   0     Braeburn Apples           1.49
   1     Fuji Apples               1.29
   2     Gala Apples               1.49
   3     Golden Delicious Apples   1.29
   4     Granny Smith Apples       0.89
   5     Red Delicious Apples      0.99

*/


import System.*;
import System.Collections.*;
import System.Collections.Specialized.*;
import System.Collections.DictionaryEntry;

public class SamplesListDictionary
{
    public static void main(String[] args)
    {
        // Creates and initializes a new ListDictionary.
        ListDictionary myCol = new ListDictionary();

        myCol.Add("Braeburn Apples", "1.49");
        myCol.Add("Fuji Apples", "1.29");
        myCol.Add("Gala Apples", "1.49");
        myCol.Add("Golden Delicious Apples", "1.29");
        myCol.Add("Granny Smith Apples", "0.89");
        myCol.Add("Red Delicious Apples", "0.99");

        // Display the contents of the collection using for. This is the
        // preferred method.
        Console.WriteLine("Displays the elements using for:");
        PrintKeysAndValues1(myCol);

        // Display the contents of the collection using the enumerator.
        Console.WriteLine("Displays the elements using the"
            + " IDictionaryEnumerator:");
        PrintKeysAndValues2(myCol);

        // Display the contents of the collection using the Keys, Values, Count,
        // and Item properties.
        Console.WriteLine("Displays the elements using the Keys, Values,"
            + " Count, and Item properties:");
        PrintKeysAndValues3(myCol);
    } //main

    // Uses the for statement which hides the complexity of the enumerator.
    // NOTE: The for statement is the preferred way of enumerating the
    // contents of a collection.
    public static void PrintKeysAndValues1(IDictionary myCol)
    {
        String strKeys[] = new String[myCol.get_Count()];
        myCol.get_Keys().CopyTo(strKeys,0);

        Console.WriteLine("   KEY                       VALUE");
        for (int iCtr=0; iCtr < myCol.get_Count(); iCtr++) {
            Console.WriteLine("   {0,-25} {1}", strKeys[iCtr],
                myCol.get_Item(strKeys[iCtr]));
        }
        Console.WriteLine();
    } //PrintKeysAndValues1

    // Uses the enumerator. 
    // NOTE: The for statement is the preferred way of enumerating the
    // contents of a collection.
    public static void PrintKeysAndValues2(IDictionary myCol)
    {
        IDictionaryEnumerator myEnumerator = myCol.GetEnumerator();

        Console.WriteLine("   KEY                       VALUE");
        while (myEnumerator.MoveNext()) {
            Console.WriteLine("   {0,-25} {1}", myEnumerator.get_Key(),
            myEnumerator.get_Value());
        }

        Console.WriteLine();
    } //PrintKeysAndValues2

    // Uses the Keys, Values, Count, and Item properties.
    public static void PrintKeysAndValues3(ListDictionary myCol)
    {
        String myKeys[] = new String[myCol.get_Count()];

        myCol.get_Keys().CopyTo(myKeys, 0);
        Console.WriteLine("   INDEX KEY                       VALUE");
        for (int i = 0; i < myCol.get_Count(); i++) {
            Console.WriteLine("   {0,-5} {1,-25} {2}",  (Int32)i, myKeys[i], 
                myCol.get_Item(myKeys[i]));
        }
        Console.WriteLine();
    }//PrintKeysAndValues3
}//SamplesListDictionary
 
/*
This code produces the following output.

Displays the elements using for:
   KEY                       VALUE
   Braeburn Apples           1.49
   Fuji Apples               1.29
   Gala Apples               1.49
   Golden Delicious Apples   1.29
   Granny Smith Apples       0.89
   Red Delicious Apples      0.99

Displays the elements using the IDictionaryEnumerator:
   KEY                       VALUE
   Braeburn Apples           1.49
   Fuji Apples               1.29
   Gala Apples               1.49
   Golden Delicious Apples   1.29
   Granny Smith Apples       0.89
   Red Delicious Apples      0.99

Displays the elements using the Keys, Values, Count, and Item properties:
   INDEX KEY                       VALUE
   0     Braeburn Apples           1.49
   1     Fuji Apples               1.29
   2     Gala Apples               1.49
   3     Golden Delicious Apples   1.29
   4     Granny Smith Apples       0.89
   5     Red Delicious Apples      0.99

*/

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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