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BitVector32 Structure

Provides a simple structure that stores Boolean values and small integers in 32 bits of memory.

For a list of all members of this type, see BitVector32 Members.

System.Object
   System.ValueType
      System.Collections.Specialized.BitVector32

[Visual Basic]
Public Structure BitVector32
[C#]
public struct BitVector32
[C++]
public __value struct BitVector32

[JScript] In JScript, you can use the structures in the .NET Framework, but you cannot define your own.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Remarks

BitVector32 is more efficient than BitArray for Boolean values and small integers that are used internally. A BitArray can grow indefinitely as needed, but it has the memory and performance overhead that a class instance requires. In contrast, a BitVector32 uses only 32 bits.

A BitVector32 structure can be set up to contain either sections for small integers or bit flags for Booleans, but not both. A BitVector32.Section is a window into the BitVector32 and is composed of the smallest number of consecutive bits that can contain the maximum value specified in CreateSection. For example, a section with a maximum value of 1 is composed of only one bit, whereas a section with a maximum value of 5 is composed of three bits. You can create a BitVector32.Section with a maximum value of 1 to serve as a Boolean, thereby allowing you to store integers and Booleans in the same BitVector32.

Some members can be used for a BitVector32 that is set up as sections, while other members can be used for one that is set up as bit flags. For example, the Item [Section] property is the indexer for a BitVector32 that is set up as sections, and the Item [int] property is the indexer for a BitVector32 that is set up as bit flags. CreateMask creates a series of masks that can be used to access individual bits in a BitVector32 that is set up as bit flags.

Using a mask on a BitVector32 that is set up as sections might cause unexpected results.

Example

[Visual Basic, C#, C++] The following code example uses a BitVector32 as a collection of bit flags.

[Visual Basic] 
Imports System
Imports System.Collections.Specialized

Public Class SamplesBitVector32

   Public Shared Sub Main()

      ' Creates and initializes a BitVector32 with all bit flags set to FALSE.
      Dim myBV As New BitVector32(0)

      ' Creates masks to isolate each of the first five bit flags.
      Dim myBit1 As Integer = BitVector32.CreateMask()
      Dim myBit2 As Integer = BitVector32.CreateMask(myBit1)
      Dim myBit3 As Integer = BitVector32.CreateMask(myBit2)
      Dim myBit4 As Integer = BitVector32.CreateMask(myBit3)
      Dim myBit5 As Integer = BitVector32.CreateMask(myBit4)

      ' Sets the alternating bits to TRUE.
      Console.WriteLine("Setting alternating bits to TRUE:")
      Console.WriteLine("   Initial:         {0}", myBV.ToString())
      myBV(myBit1) = True
      Console.WriteLine("   myBit1 = TRUE:   {0}", myBV.ToString())
      myBV(myBit3) = True
      Console.WriteLine("   myBit3 = TRUE:   {0}", myBV.ToString())
      myBV(myBit5) = True
      Console.WriteLine("   myBit5 = TRUE:   {0}", myBV.ToString())
   End Sub 'Main 
End Class 'SamplesBitVector32


' This code produces the following output.
'
' Setting alternating bits to TRUE:
'    Initial:         BitVector32{00000000000000000000000000000000}
'    myBit1 = TRUE:   BitVector32{00000000000000000000000000000001}
'    myBit3 = TRUE:   BitVector32{00000000000000000000000000000101}
'    myBit5 = TRUE:   BitVector32{00000000000000000000000000010101}


[C#] 
using System;
using System.Collections.Specialized;


public class SamplesBitVector32  {

   public static void Main()  {

      // Creates and initializes a BitVector32 with all bit flags set to FALSE.
      BitVector32 myBV = new BitVector32( 0 );

      // Creates masks to isolate each of the first five bit flags.
      int myBit1 = BitVector32.CreateMask();
      int myBit2 = BitVector32.CreateMask( myBit1 );
      int myBit3 = BitVector32.CreateMask( myBit2 );
      int myBit4 = BitVector32.CreateMask( myBit3 );
      int myBit5 = BitVector32.CreateMask( myBit4 );

      // Sets the alternating bits to TRUE.
      Console.WriteLine( "Setting alternating bits to TRUE:" );
      Console.WriteLine( "   Initial:         {0}", myBV.ToString() );
      myBV[myBit1] = true;
      Console.WriteLine( "   myBit1 = TRUE:   {0}", myBV.ToString() );
      myBV[myBit3] = true;
      Console.WriteLine( "   myBit3 = TRUE:   {0}", myBV.ToString() );
      myBV[myBit5] = true;
      Console.WriteLine( "   myBit5 = TRUE:   {0}", myBV.ToString() );

   }

}

/*
This code produces the following output.

Setting alternating bits to TRUE:
   Initial:         BitVector32{00000000000000000000000000000000}
   myBit1 = TRUE:   BitVector32{00000000000000000000000000000001}
   myBit3 = TRUE:   BitVector32{00000000000000000000000000000101}
   myBit5 = TRUE:   BitVector32{00000000000000000000000000010101}


*/

[C++] 
#using <mscorlib.dll>
#using <system.dll>

using namespace System;
using namespace System::Collections::Specialized;

int main()
{
   // Creates and initializes a BitVector32 with all bit flags set to FALSE.
   BitVector32 myBV(0);

   // Creates masks to isolate each of the first five bit flags.
   int myBit1 = BitVector32::CreateMask();
   int myBit2 = BitVector32::CreateMask(myBit1);
   int myBit3 = BitVector32::CreateMask(myBit2);
   int myBit4 = BitVector32::CreateMask(myBit3);
   int myBit5 = BitVector32::CreateMask(myBit4);

   // Sets the alternating bits to TRUE.
   Console::WriteLine(S"Setting alternating bits to TRUE:");
   Console::WriteLine(S"   Initial:       {0}", __box(myBV));
   myBV.Item[myBit1] = true;
   Console::WriteLine(S"   myBit1 = TRUE: {0}", __box(myBV));
   myBV.Item[myBit3] = true;
   Console::WriteLine(S"   myBit3 = TRUE: {0}", __box(myBV));
   myBV.Item[myBit5] = true;
   Console::WriteLine(S"   myBit5 = TRUE: {0}", __box(myBV));
}

/*
This code produces the following output.

Setting alternating bits to TRUE:
Initial:         BitVector32 {00000000000000000000000000000000}
myBit1 = TRUE:   BitVector32 {00000000000000000000000000000001}
myBit3 = TRUE:   BitVector32 {00000000000000000000000000000101}
myBit5 = TRUE:   BitVector32 {00000000000000000000000000010101}


*/

[Visual Basic, C#, C++] The following code example uses a BitVector32 as a collection of sections.

[Visual Basic] 
Imports System
Imports System.Collections.Specialized

Public Class SamplesBitVector32
   
   Public Shared Sub Main()
      
      ' Creates and initializes a BitVector32.
      Dim myBV As New BitVector32(0)
      
      ' Creates four sections in the BitVector32 with maximum values 6, 3, 1, and 15.
      ' mySect3, which uses exactly one bit, can also be used as a bit flag.
      Dim mySect1 As BitVector32.Section = BitVector32.CreateSection(6)
      Dim mySect2 As BitVector32.Section = BitVector32.CreateSection(3, mySect1)
      Dim mySect3 As BitVector32.Section = BitVector32.CreateSection(1, mySect2)
      Dim mySect4 As BitVector32.Section = BitVector32.CreateSection(15, mySect3)
      
      ' Displays the values of the sections.
      Console.WriteLine("Initial values:")
      Console.WriteLine(ControlChars.Tab + "mySect1: {0}", myBV(mySect1))
      Console.WriteLine(ControlChars.Tab + "mySect2: {0}", myBV(mySect2))
      Console.WriteLine(ControlChars.Tab + "mySect3: {0}", myBV(mySect3))
      Console.WriteLine(ControlChars.Tab + "mySect4: {0}", myBV(mySect4))
      
      ' Sets each section to a new value and displays the value of the BitVector32 at each step.
      Console.WriteLine("Changing the values of each section:")
      Console.WriteLine(ControlChars.Tab + "Initial:    " + ControlChars.Tab + "{0}", myBV.ToString())
      myBV(mySect1) = 5
      Console.WriteLine(ControlChars.Tab + "mySect1 = 5:" + ControlChars.Tab + "{0}", myBV.ToString())
      myBV(mySect2) = 3
      Console.WriteLine(ControlChars.Tab + "mySect2 = 3:" + ControlChars.Tab + "{0}", myBV.ToString())
      myBV(mySect3) = 1
      Console.WriteLine(ControlChars.Tab + "mySect3 = 1:" + ControlChars.Tab + "{0}", myBV.ToString())
      myBV(mySect4) = 9
      Console.WriteLine(ControlChars.Tab + "mySect4 = 9:" + ControlChars.Tab + "{0}", myBV.ToString())
      
      ' Displays the values of the sections.
      Console.WriteLine("New values:")
      Console.WriteLine(ControlChars.Tab + "mySect1: {0}", myBV(mySect1))
      Console.WriteLine(ControlChars.Tab + "mySect2: {0}", myBV(mySect2))
      Console.WriteLine(ControlChars.Tab + "mySect3: {0}", myBV(mySect3))
      Console.WriteLine(ControlChars.Tab + "mySect4: {0}", myBV(mySect4))

   End Sub 'Main 

End Class 'SamplesBitVector32


' This code produces the following output.
'
' Initial values:
'        mySect1: 0
'        mySect2: 0
'        mySect3: 0
'        mySect4: 0
' Changing the values of each section:
'        Initial:        BitVector32{00000000000000000000000000000000}
'        mySect1 = 5:    BitVector32{00000000000000000000000000000101}
'        mySect2 = 3:    BitVector32{00000000000000000000000000011101}
'        mySect3 = 1:    BitVector32{00000000000000000000000000111101}
'        mySect4 = 9:    BitVector32{00000000000000000000001001111101}
' New values:
'        mySect1: 5
'        mySect2: 3
'        mySect3: 1
'        mySect4: 9

[C#] 
using System;
using System.Collections.Specialized;


public class SamplesBitVector32  {

   public static void Main()  {

      // Creates and initializes a BitVector32.
      BitVector32 myBV = new BitVector32( 0 );

      // Creates four sections in the BitVector32 with maximum values 6, 3, 1, and 15.
      // mySect3, which uses exactly one bit, can also be used as a bit flag.
      BitVector32.Section mySect1 = BitVector32.CreateSection( 6 );
      BitVector32.Section mySect2 = BitVector32.CreateSection( 3, mySect1 );
      BitVector32.Section mySect3 = BitVector32.CreateSection( 1, mySect2 );
      BitVector32.Section mySect4 = BitVector32.CreateSection( 15, mySect3 );

      // Displays the values of the sections.
      Console.WriteLine( "Initial values:" );
      Console.WriteLine( "\tmySect1: {0}", myBV[mySect1] );
      Console.WriteLine( "\tmySect2: {0}", myBV[mySect2] );
      Console.WriteLine( "\tmySect3: {0}", myBV[mySect3] );
      Console.WriteLine( "\tmySect4: {0}", myBV[mySect4] );

      // Sets each section to a new value and displays the value of the BitVector32 at each step.
      Console.WriteLine( "Changing the values of each section:" );
      Console.WriteLine( "\tInitial:    \t{0}", myBV.ToString() );
      myBV[mySect1] = 5;
      Console.WriteLine( "\tmySect1 = 5:\t{0}", myBV.ToString() );
      myBV[mySect2] = 3;
      Console.WriteLine( "\tmySect2 = 3:\t{0}", myBV.ToString() );
      myBV[mySect3] = 1;
      Console.WriteLine( "\tmySect3 = 1:\t{0}", myBV.ToString() );
      myBV[mySect4] = 9;
      Console.WriteLine( "\tmySect4 = 9:\t{0}", myBV.ToString() );

      // Displays the values of the sections.
      Console.WriteLine( "New values:" );
      Console.WriteLine( "\tmySect1: {0}", myBV[mySect1] );
      Console.WriteLine( "\tmySect2: {0}", myBV[mySect2] );
      Console.WriteLine( "\tmySect3: {0}", myBV[mySect3] );
      Console.WriteLine( "\tmySect4: {0}", myBV[mySect4] );

   }

}

/*
This code produces the following output.

Initial values:
        mySect1: 0
        mySect2: 0
        mySect3: 0
        mySect4: 0
Changing the values of each section:
        Initial:        BitVector32{00000000000000000000000000000000}
        mySect1 = 5:    BitVector32{00000000000000000000000000000101}
        mySect2 = 3:    BitVector32{00000000000000000000000000011101}
        mySect3 = 1:    BitVector32{00000000000000000000000000111101}
        mySect4 = 9:    BitVector32{00000000000000000000001001111101}
New values:
        mySect1: 5
        mySect2: 3
        mySect3: 1
        mySect4: 9

*/

[C++] 
#using <mscorlib.dll>
#using <system.dll>

using namespace System;
using namespace System::Collections::Specialized;

int main()
{
   // Creates and initializes a BitVector32.
   BitVector32 myBV(0);

   // Creates four sections in the BitVector32 with maximum values 6, 3, 1, and 15.
   // mySect3, which uses exactly one bit, can also be used as a bit flag.
   BitVector32::Section mySect1 = BitVector32::CreateSection(6);
   BitVector32::Section mySect2 = BitVector32::CreateSection(3, mySect1);
   BitVector32::Section mySect3 = BitVector32::CreateSection(1, mySect2);
   BitVector32::Section mySect4 = BitVector32::CreateSection(15, mySect3);

   // Displays the values of the sections.
   Console::WriteLine(S"Initial values:");
   Console::WriteLine(S"\tmySect1: {0}", __box(myBV.Item[mySect1]));
   Console::WriteLine(S"\tmySect2: {0}", __box(myBV.Item[mySect2]));
   Console::WriteLine(S"\tmySect3: {0}", __box(myBV.Item[mySect3]));
   Console::WriteLine(S"\tmySect4: {0}", __box(myBV.Item[mySect4]));

   // Sets each section to a new value and displays the value of the BitVector32 at each step.
   Console::WriteLine(S"Changing the values of each section:");
   Console::WriteLine(S"\tInitial:    \t {0}", __box(myBV));
   myBV.Item[mySect1] = 5;
   Console::WriteLine(S"\tmySect1 = 5:\t {0}", __box(myBV));
   myBV.Item[mySect2] = 3;
   Console::WriteLine(S"\tmySect2 = 3:\t {0}", __box(myBV));
   myBV.Item[mySect3] = 1;
   Console::WriteLine(S"\tmySect3 = 1:\t {0}", __box(myBV));
   myBV.Item[mySect4] = 9;
   Console::WriteLine(S"\tmySect4 = 9:\t {0}", __box(myBV));

   // Displays the values of the sections.
   Console::WriteLine(S"New values:");
   Console::WriteLine(S"\tmySect1: {0}", __box(myBV.Item[mySect1]));
   Console::WriteLine(S"\tmySect2: {0}", __box(myBV.Item[mySect2]));
   Console::WriteLine(S"\tmySect3: {0}", __box(myBV.Item[mySect3]));
   Console::WriteLine(S"\tmySect4: {0}", __box(myBV.Item[mySect4]));
}

/*
This code produces the following output.

Initial values:
        mySect1: 0
        mySect2: 0
        mySect3: 0
        mySect4: 0
Changing the values of each section:
        Initial:        BitVector32 {00000000000000000000000000000000}
        mySect1 = 5:    BitVector32 {00000000000000000000000000000101}
        mySect2 = 3:    BitVector32 {00000000000000000000000000011101}
        mySect3 = 1:    BitVector32 {00000000000000000000000000111101}
        mySect4 = 9:    BitVector32 {00000000000000000000001001111101}
New values:
        mySect1: 5
        mySect2: 3
        mySect3: 1
        mySect4: 9

*/

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Namespace: System.Collections.Specialized

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

Assembly: System (in System.dll)

See Also

BitVector32 Members | System.Collections.Specialized Namespace | BitArray

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