Array.Sort Method (Array, Int32, Int32) (System)

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.NET Framework Class Library

Array.Sort Method (Array, Int32, Int32)

Sorts the elements in a range of elements in a one-dimensional Array using the IComparable implementation of each element of the Array.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

Syntax

Visual Basic

Public Shared Sub Sort ( _
	array As Array, _
	index As Integer, _
	length As Integer _
)

public static void Sort(
	Array array,
	int index,
	int length
)

Visual C++

public:
static void Sort(
	Array^ array, 
	int index, 
	int length
)

static member Sort : 
        array:Array * 
        index:int * 
        length:int -> unit

Parameters

array: Type: System.Array
The one-dimensional Array to sort.

index: Type: System.Int32
The starting index of the range to sort.

length: Type: System.Int32
The number of elements in the range to sort.

Exceptions

Exception	Condition
ArgumentNullException	array is null.
RankException	array is multidimensional.
ArgumentOutOfRangeException	index is less than the lower bound of array. -or- length is less than zero.
ArgumentException	index and length do not specify a valid range in array.
InvalidOperationException	One or more elements in array do not implement the IComparable interface.

Remarks

Each element within the specified range of elements in array must implement the IComparable interface to be capable of comparisons with every other element in array.

If the sort is not successfully completed, the results are undefined.

This method uses the QuickSort algorithm. This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal.

On average, this method is an O(n log n) operation, where n is length; in the worst case it is an O(n ^ 2) operation.

Examples

The following code example shows how to sort the values in an Array using the default comparer and a custom comparer that reverses the sort order. Note that the result might vary depending on the current CultureInfo.

Visual Basic


Imports System
Imports System.Collections

Public Class SamplesArray

   Public Class myReverserClass
      Implements IComparer

      ' Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      Function Compare(x As Object, y As Object) As Integer _
         Implements IComparer.Compare
         Return New CaseInsensitiveComparer().Compare(y, x)
      End Function 'IComparer.Compare

   End Class 'myReverserClass

   Public Shared Sub Main()

      ' Creates and initializes a new Array and a new custom comparer.
      Dim myArr As [String]() =  {"The", "QUICK", "BROWN", "FOX", "jumps", "over", "the", "lazy", "dog"}
      Dim myComparer = New myReverserClass()

      ' Displays the values of the Array.
      Console.WriteLine("The Array initially contains the following values:")
      PrintIndexAndValues(myArr)

      ' Sorts a section of the Array using the default comparer.
      Array.Sort(myArr, 1, 3)
      Console.WriteLine("After sorting a section of the Array using the default comparer:")
      PrintIndexAndValues(myArr)

      ' Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort(myArr, 1, 3, myComparer)
      Console.WriteLine("After sorting a section of the Array using the reverse case-insensitive comparer:")
      PrintIndexAndValues(myArr)

      ' Sorts the entire Array using the default comparer.
      Array.Sort(myArr)
      Console.WriteLine("After sorting the entire Array using the default comparer:")
      PrintIndexAndValues(myArr)

      ' Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort(myArr, myComparer)
      Console.WriteLine("After sorting the entire Array using the reverse case-insensitive comparer:")
      PrintIndexAndValues(myArr)

   End Sub 'Main

   Public Shared Sub PrintIndexAndValues(myArr() As [String])

      Dim i As Integer
      For i = 0 To myArr.Length - 1
         Console.WriteLine("   [{0}] : {1}", i, myArr(i))
      Next i
      Console.WriteLine()

   End Sub 'PrintIndexAndValues

End Class 'SamplesArray


'This code produces the following output.
'
'The Array initially contains the following values:
'   [0] : The
'   [1] : QUICK
'   [2] : BROWN
'   [3] : FOX
'   [4] : jumps
'   [5] : over
'   [6] : the
'   [7] : lazy
'   [8] : dog
'
'After sorting a section of the Array using the default comparer:
'   [0] : The
'   [1] : BROWN
'   [2] : FOX
'   [3] : QUICK
'   [4] : jumps
'   [5] : over
'   [6] : the
'   [7] : lazy
'   [8] : dog
'
'After sorting a section of the Array using the reverse case-insensitive comparer:
'   [0] : The
'   [1] : QUICK
'   [2] : FOX
'   [3] : BROWN
'   [4] : jumps
'   [5] : over
'   [6] : the
'   [7] : lazy
'   [8] : dog
'
'After sorting the entire Array using the default comparer:
'   [0] : BROWN
'   [1] : dog
'   [2] : FOX
'   [3] : jumps
'   [4] : lazy
'   [5] : over
'   [6] : QUICK
'   [7] : the
'   [8] : The
'
'After sorting the entire Array using the reverse case-insensitive comparer:
'   [0] : the
'   [1] : The
'   [2] : QUICK
'   [3] : over
'   [4] : lazy
'   [5] : jumps
'   [6] : FOX
'   [7] : dog
'   [8] : BROWN


using System;
using System.Collections;

public class SamplesArray  {

   public class myReverserClass : IComparer  {

      // Calls CaseInsensitiveComparer.Compare with the parameters reversed.
      int IComparer.Compare( Object x, Object y )  {
          return( (new CaseInsensitiveComparer()).Compare( y, x ) );
      }

   }

   public static void Main()  {

      // Creates and initializes a new Array and a new custom comparer.
      String[] myArr = { "The", "QUICK", "BROWN", "FOX", "jumps", "over", "the", "lazy", "dog" };
      IComparer myComparer = new myReverserClass();

      // Displays the values of the Array.
      Console.WriteLine( "The Array initially contains the following values:" );
      PrintIndexAndValues( myArr );

      // Sorts a section of the Array using the default comparer.
      Array.Sort( myArr, 1, 3 );
      Console.WriteLine( "After sorting a section of the Array using the default comparer:" );
      PrintIndexAndValues( myArr );

      // Sorts a section of the Array using the reverse case-insensitive comparer.
      Array.Sort( myArr, 1, 3, myComparer );
      Console.WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
      PrintIndexAndValues( myArr );

      // Sorts the entire Array using the default comparer.
      Array.Sort( myArr );
      Console.WriteLine( "After sorting the entire Array using the default comparer:" );
      PrintIndexAndValues( myArr );

      // Sorts the entire Array using the reverse case-insensitive comparer.
      Array.Sort( myArr, myComparer );
      Console.WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
      PrintIndexAndValues( myArr );

   }

   public static void PrintIndexAndValues( String[] myArr )  {
      for ( int i = 0; i < myArr.Length; i++ )  {
         Console.WriteLine( "   [{0}] : {1}", i, myArr[i] );
      }
      Console.WriteLine();
   }
}


/* 
This code produces the following output.

The Array initially contains the following values:
   [0] : The
   [1] : QUICK
   [2] : BROWN
   [3] : FOX
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the default comparer:
   [0] : The
   [1] : BROWN
   [2] : FOX
   [3] : QUICK
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the reverse case-insensitive comparer:
   [0] : The
   [1] : QUICK
   [2] : FOX
   [3] : BROWN
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting the entire Array using the default comparer:
   [0] : BROWN
   [1] : dog
   [2] : FOX
   [3] : jumps
   [4] : lazy
   [5] : over
   [6] : QUICK
   [7] : the
   [8] : The

After sorting the entire Array using the reverse case-insensitive comparer:
   [0] : the
   [1] : The
   [2] : QUICK
   [3] : over
   [4] : lazy
   [5] : jumps
   [6] : FOX
   [7] : dog
   [8] : BROWN

*/

Visual C++


using namespace System;
using namespace System::Collections;
public ref class myReverserClass: public IComparer
{
private:
   // Calls CaseInsensitiveComparer::Compare with the parameters reversed.
   virtual int Compare( Object^ x, Object^ y ) = IComparer::Compare
   {
      return ((gcnew CaseInsensitiveComparer)->Compare( y, x ));
   }

};

void PrintIndexAndValues( array<String^>^myArr )
{
   for ( int i = 0; i < myArr->Length; i++ )
   {
      Console::WriteLine( "   [{0}] : {1}", i, myArr[ i ] );

   }
   Console::WriteLine();
}

int main()
{

   // Creates and initializes a new Array and a new custom comparer.
   array<String^>^myArr = {"The","QUICK","BROWN","FOX","jumps","over","the","lazy","dog"};
   IComparer^ myComparer = gcnew myReverserClass;

   // Displays the values of the Array.
   Console::WriteLine( "The Array initially contains the following values:" );
   PrintIndexAndValues( myArr );

   // Sorts a section of the Array using the default comparer.
   Array::Sort( myArr, 1, 3 );
   Console::WriteLine( "After sorting a section of the Array using the default comparer:" );
   PrintIndexAndValues( myArr );

   // Sorts a section of the Array using the reverse case-insensitive comparer.
   Array::Sort( myArr, 1, 3, myComparer );
   Console::WriteLine( "After sorting a section of the Array using the reverse case-insensitive comparer:" );
   PrintIndexAndValues( myArr );

   // Sorts the entire Array using the default comparer.
   Array::Sort( myArr );
   Console::WriteLine( "After sorting the entire Array using the default comparer:" );
   PrintIndexAndValues( myArr );

   // Sorts the entire Array using the reverse case-insensitive comparer.
   Array::Sort( myArr, myComparer );
   Console::WriteLine( "After sorting the entire Array using the reverse case-insensitive comparer:" );
   PrintIndexAndValues( myArr );
}

/* 
This code produces the following output.

The Array initially contains the following values:
   [0] : The
   [1] : QUICK
   [2] : BROWN
   [3] : FOX
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the default comparer:
   [0] : The
   [1] : BROWN
   [2] : FOX
   [3] : QUICK
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting a section of the Array using the reverse case-insensitive comparer:
   [0] : The
   [1] : QUICK
   [2] : FOX
   [3] : BROWN
   [4] : jumps
   [5] : over
   [6] : the
   [7] : lazy
   [8] : dog

After sorting the entire Array using the default comparer:
   [0] : BROWN
   [1] : dog
   [2] : FOX
   [3] : jumps
   [4] : lazy
   [5] : over
   [6] : QUICK
   [7] : the
   [8] : The

After sorting the entire Array using the reverse case-insensitive comparer:
   [0] : the
   [1] : The
   [2] : QUICK
   [3] : over
   [4] : lazy
   [5] : jumps
   [6] : FOX
   [7] : dog
   [8] : BROWN

*/

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

Array Class

Sort Overload

System Namespace

IComparable

BinarySearch

Other Resources

Performing Culture-Insensitive String Operations in Arrays