Note: This method is new in the .NET Framework version 2.0.
Sorts the elements in an
Array using the specified
Comparison.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Visual Basic (Declaration)
Public Shared Sub Sort(Of T) ( _
array As T(), _
comparison As Comparison(Of T) _
)
Dim array As T()
Dim comparison As Comparison(Of T)
Array.Sort(array, comparison)
public static void Sort<T> (
T[] array,
Comparison<T> comparison
)
public:
generic<typename T>
static void Sort (
array<T>^ array,
Comparison<T>^ comparison
)
J# supports the use of generic types and methods, but not the declaration of new ones.
JScript does not support generic types and methods.
Type Parameters
- T
The type of the elements of the array.
Parameters
- array
The one-dimensional, zero-based Array to sort
- comparison
The Comparison to use when comparing elements.
| Exception type | Condition |
|---|
ArgumentNullException | array is a null reference (Nothing in Visual Basic). -or- comparison is a null reference (Nothing in Visual Basic). |
ArgumentException | The implementation of comparison caused an error during the sort. For example, comparison might not return 0 when comparing an item with itself. |
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 the Length of array; in the worst case it is an O(n ^ 2) operation.
The following code example demonstrates the Sort(Generic Comparison) method overload.
The code example defines an alternative comparison method for strings, named CompareDinosByLength. This method works as follows: First, the comparands are tested for a null reference (Nothing in Visual Basic), and a null reference is treated as less than a non-null. Second, the string lengths are compared, and the longer string is deemed to be greater. Third, if the lengths are equal, ordinary string comparison is used.
A array of strings is created and populated with four strings, in no particular order. The list also includes an empty string and a null reference. The list is displayed, sorted using a Comparison generic delegate representing the CompareDinosByLength method, and displayed again.
Imports System
Imports System.Collections.Generic
Public Class Example
Private Shared Function CompareDinosByLength( _
ByVal x As String, ByVal y As String) As Integer
If x Is Nothing Then
If y Is Nothing Then
' If x is Nothing and y is Nothing, they're
' equal.
Return 0
Else
' If x is Nothing and y is not Nothing, y
' is greater.
Return -1
End If
Else
' If x is not Nothing...
'
If y Is Nothing Then
' ...and y is Nothing, x is greater.
Return 1
Else
' ...and y is not Nothing, compare the
' lengths of the two strings.
'
Dim retval As Integer = _
x.Length.CompareTo(y.Length)
If retval <> 0 Then
' If the strings are not of equal length,
' the longer string is greater.
'
Return retval
Else
' If the strings are of equal length,
' sort them with ordinary string comparison.
'
Return x.CompareTo(y)
End If
End If
End If
End Function
Public Shared Sub Main()
Dim dinosaurs() As String = { _
"Pachycephalosaurus", _
"Amargasaurus", _
"", _
Nothing, _
"Mamenchisaurus", _
"Deinonychus" }
Display(dinosaurs)
Console.WriteLine(vbLf & "Sort with generic Comparison(Of String) delegate:")
Array.Sort(dinosaurs, AddressOf CompareDinosByLength)
Display(dinosaurs)
End Sub
Private Shared Sub Display(ByVal arr() As String)
Console.WriteLine()
For Each s As String In arr
If s Is Nothing Then
Console.WriteLine("(Nothing)")
Else
Console.WriteLine("""{0}""", s)
End If
Next
End Sub
End Class
' This code example produces the following output:
'
'"Pachycephalosaurus"
'"Amargasaurus"
'""
'(Nothing)
'"Mamenchisaurus"
'"Deinonychus"
'
'Sort with generic Comparison(Of String) delegate:
'
'(Nothing)
'""
'"Deinonychus"
'"Amargasaurus"
'"Mamenchisaurus"
'"Pachycephalosaurus"
using System;
using System.Collections.Generic;
public class Example
{
private static int CompareDinosByLength(string x, string y)
{
if (x == null)
{
if (y == null)
{
// If x is null and y is null, they're
// equal.
return 0;
}
else
{
// If x is null and y is not null, y
// is greater.
return -1;
}
}
else
{
// If x is not null...
//
if (y == null)
// ...and y is null, x is greater.
{
return 1;
}
else
{
// ...and y is not null, compare the
// lengths of the two strings.
//
int retval = x.Length.CompareTo(y.Length);
if (retval != 0)
{
// If the strings are not of equal length,
// the longer string is greater.
//
return retval;
}
else
{
// If the strings are of equal length,
// sort them with ordinary string comparison.
//
return x.CompareTo(y);
}
}
}
}
public static void Main()
{
string[] dinosaurs = {
"Pachycephalosaurus",
"Amargasaurus",
"",
null,
"Mamenchisaurus",
"Deinonychus" };
Display(dinosaurs);
Console.WriteLine("\nSort with generic Comparison<string> delegate:");
Array.Sort(dinosaurs, CompareDinosByLength);
Display(dinosaurs);
}
private static void Display(string[] arr)
{
Console.WriteLine();
foreach( string s in arr )
{
if (s == null)
Console.WriteLine("(null)");
else
Console.WriteLine("\"{0}\"", s);
}
}
}
/* This code example produces the following output:
"Pachycephalosaurus"
"Amargasaurus"
""
(null)
"Mamenchisaurus"
"Deinonychus"
Sort with generic Comparison<string> delegate:
(null)
""
"Deinonychus"
"Amargasaurus"
"Mamenchisaurus"
"Pachycephalosaurus"
*/
using namespace System;
using namespace System::Collections::Generic;
int CompareDinosByLength(String^ x, String^ y)
{
if (x == nullptr)
{
if (y == nullptr)
{
// If x is null and y is null, they're
// equal.
return 0;
}
else
{
// If x is null and y is not null, y
// is greater.
return -1;
}
}
else
{
// If x is not null...
//
if (y == nullptr)
// ...and y is null, x is greater.
{
return 1;
}
else
{
// ...and y is not null, compare the
// lengths of the two strings.
//
int retval = x->Length.CompareTo(y->Length);
if (retval != 0)
{
// If the strings are not of equal length,
// the longer string is greater.
//
return retval;
}
else
{
// If the strings are of equal length,
// sort them with ordinary string comparison.
//
return x->CompareTo(y);
}
}
}
};
void Display(array<String^>^ arr)
{
Console::WriteLine();
for each(String^ s in arr)
{
if (s == nullptr)
Console::WriteLine("(null)");
else
Console::WriteLine("\"{0}\"", s);
}
};
void main()
{
array<String^>^ dinosaurs = {
"Pachycephalosaurus",
"Amargasaurus",
"",
nullptr,
"Mamenchisaurus",
"Deinonychus" };
Display(dinosaurs);
Console::WriteLine("\nSort with generic Comparison<String^> delegate:");
Array::Sort(dinosaurs,
gcnew Comparison<String^>(CompareDinosByLength));
Display(dinosaurs);
}
/* This code example produces the following output:
"Pachycephalosaurus"
"Amargasaurus"
""
(null)
"Mamenchisaurus"
"Deinonychus"
Sort with generic Comparison<String^> delegate:
(null)
""
"Deinonychus"
"Amargasaurus"
"Mamenchisaurus"
"Pachycephalosaurus"
*/
Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
.NET Framework
Supported in: 2.0
.NET Compact Framework
Supported in: 2.0