Array.Sort(TKey, TValue) Method (TKey[], TValue[], Int32, Int32) (System)

.NET Framework Class Library

Array..::.Sort<(Of <(TKey, TValue>)>) Method (array<TKey>[]()[], array<TValue>[]()[], Int32, Int32)

Sorts a range of elements in a pair of Array objects (one contains the keys and the other contains the corresponding items) based on the keys in the first Array using the IComparable<(Of <(T>)>) generic interface implementation of each key.

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

Syntax

Public Shared Sub Sort(Of TKey, TValue) ( _
	keys As TKey(), _
	items As TValue(), _
	index As Integer, _
	length As Integer _
)

public static void Sort<TKey, TValue>(
	TKey[] keys,
	TValue[] items,
	int index,
	int length
)

public:
generic<typename TKey, typename TValue>
static void Sort(
	array<TKey>^ keys, 
	array<TValue>^ items, 
	int index, 
	int length
)

static member Sort : 
        keys:'TKey[] * 
        items:'TValue[] * 
        index:int * 
        length:int -> unit

Type Parameters

TKey: The type of the elements of the key array.

TValue: The type of the elements of the items array.

Parameters

keys: Type: array<TKey>[]()[]
The one-dimensional, zero-based Array that contains the keys to sort.

items: Type: array<TValue>[]()[]
The one-dimensional, zero-based Array that contains the items that correspond to the keys in keys, or nullNothingnullptra null reference (Nothing in Visual Basic) to sort only keys.

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	keys is nullNothingnullptra null reference (Nothing in Visual Basic).
ArgumentOutOfRangeException	index is less than the lower bound of keys. -or- length is less than zero.
ArgumentException	items is not nullNothingnullptra null reference (Nothing in Visual Basic), and the lower bound of keys does not match the lower bound of items. -or- items is not nullNothingnullptra null reference (Nothing in Visual Basic), and the length of keys is greater than the length of items. -or- index and length do not specify a valid range in the keysArray. -or- items is not nullNothingnullptra null reference (Nothing in Visual Basic), and index and length do not specify a valid range in the itemsArray.
InvalidOperationException	One or more elements in the keysArray do not implement the IComparable<(Of <(T>)>) generic interface.

Remarks

Each key in the keysArray has a corresponding item in the itemsArray. When a key is repositioned during the sorting, the corresponding item in the itemsArray is similarly repositioned. Therefore, the itemsArray is sorted according to the arrangement of the corresponding keys in the keysArray.

Each key within the specified range of elements in the keysArray must implement the IComparable<(Of <(T>)>) generic interface to be capable of comparisons with every other key.

You can sort if there are more items than keys, but the items that have no corresponding keys will not be sorted. You cannot sort if there are more keys than items; doing this throws an ArgumentException.

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 demonstrates the Sort<(Of <(TKey, TValue>)>)(array<TKey>[]()[], array<TValue>[]()[]), Sort<(Of <(TKey, TValue>)>)(array<TKey>[]()[], array<TValue>[]()[], IComparer<(Of <(TKey>)>)), Sort<(Of <(TKey, TValue>)>)(array<TKey>[]()[], array<TValue>[]()[], Int32, Int32), and Sort<(Of <(TKey, TValue>)>)(array<TKey>[]()[], array<TValue>[]()[], Int32, Int32, IComparer<(Of <(TKey>)>)) generic method overloads, for sorting pairs of arrays that represent keys and values.

The code example defines an alternative comparer for strings, named ReverseCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. The comparer calls the CompareTo(String) method, reversing the order of the comparands so that the strings sort high-to-low instead of low-to-high.

The code example creates and displays an array of dinosaur names (the keys) and an array of integers representing the maximum length of each dinosaur in meters (the values). The arrays are then sorted and displayed several times:

The Sort<(Of <(TKey, TValue>)>)(array<TKey>[]()[], array<TValue>[]()[]) overload is used to sort both arrays in order of the dinosaur names in the first array.
The Sort<(Of <(TKey, TValue>)>)(array<TKey>[]()[], array<TValue>[]()[], IComparer<(Of <(TKey>)>)) overload and an instance of ReverseCompare are used to reverse the sort order of the paired arrays.
The Sort<(Of <(TKey, TValue>)>)(array<TKey>[]()[], array<TValue>[]()[], Int32, Int32) overload is used to sort the last three elements of both arrays.
The Sort<(Of <(TKey, TValue>)>)(array<TKey>[]()[], array<TValue>[]()[], Int32, Int32, IComparer<(Of <(TKey>)>)) overload is used to sort the last three elements of both arrays in reverse order.

Note
The calls to the generic methods do not look any different from calls to their nongeneric counterparts, because Visual Basic, C#, and C++ infer the type of the generic type parameter from the type of the first two arguments. If you use the Ildasm.exe (MSIL Disassembler) to examine the Microsoft intermediate language (MSIL), you can see that the generic methods are being called.


Imports System
Imports System.Collections.Generic

Public Class ReverseComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        ' Compare y and x in reverse order.
        Return y.CompareTo(x)

    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs() As String = { _
            "Seismosaurus", _
            "Chasmosaurus", _
            "Coelophysis", _
            "Mamenchisaurus", _
            "Caudipteryx", _
            "Cetiosaurus"  }

        Dim dinosaurSizes() As Integer = { 40, 5, 3, 22, 1, 18 }

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes)")
        Array.Sort(dinosaurs, dinosaurSizes)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Dim rc As New ReverseComparer()

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

        Console.WriteLine(vbLf & _
            "Sort(dinosaurs, dinosaurSizes, 3, 3, rc)")
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

        Console.WriteLine()
        For i As Integer = 0 To dinosaurs.Length - 1
            Console.WriteLine("{0}: up to {1} meters long.", _
                dinosaurs(i), dinosaurSizes(i))
        Next

    End Sub

End Class

' This code example produces the following output:
'
'Seismosaurus: up to 40 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'
'Sort(dinosaurs, dinosaurSizes)
'
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'Coelophysis: up to 3 meters long.
'Mamenchisaurus: up to 22 meters long.
'Seismosaurus: up to 40 meters long.
'
'Sort(dinosaurs, dinosaurSizes, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Caudipteryx: up to 1 meters long.
'Cetiosaurus: up to 18 meters long.
'Chasmosaurus: up to 5 meters long.
'
'Sort(dinosaurs, dinosaurSizes, 3, 3, rc)
'
'Seismosaurus: up to 40 meters long.
'Mamenchisaurus: up to 22 meters long.
'Coelophysis: up to 3 meters long.
'Chasmosaurus: up to 5 meters long.
'Cetiosaurus: up to 18 meters long.
'Caudipteryx: up to 1 meters long.


using System;
using System.Collections.Generic;

public class ReverseComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        // Compare y and x in reverse order.
        return y.CompareTo(x);
    }
}

public class Example
{
    public static void Main()
    {
        string[] dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

        int[] dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes)");
        Array.Sort(dinosaurs, dinosaurSizes);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        ReverseComparer rc = new ReverseComparer();

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }

        Console.WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
        Array.Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

        Console.WriteLine();
        for (int i = 0; i < dinosaurs.Length; i++)
        {
            Console.WriteLine("{0}: up to {1} meters long.", 
                dinosaurs[i], dinosaurSizes[i]);
        }
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */


using namespace System;
using namespace System::Collections::Generic;

public ref class ReverseComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        // Compare y and x in reverse order.
        return y->CompareTo(x);
    }
};

void main()
{
    array<String^>^ dinosaurs = {
            "Seismosaurus", 
            "Chasmosaurus", 
            "Coelophysis", 
            "Mamenchisaurus", 
            "Caudipteryx", 
            "Cetiosaurus"  };

    array<int>^ dinosaurSizes = { 40, 5, 3, 22, 1, 18 };

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes)");
    Array::Sort(dinosaurs, dinosaurSizes);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    ReverseComparer^ rc = gcnew ReverseComparer();

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }

    Console::WriteLine("\nSort(dinosaurs, dinosaurSizes, 3, 3, rc)");
    Array::Sort(dinosaurs, dinosaurSizes, 3, 3, rc);

    Console::WriteLine();
    for (int i = 0; i < dinosaurs->Length; i++)
    {
        Console::WriteLine("{0}: up to {1} meters long.", 
            dinosaurs[i], dinosaurSizes[i]);
    }
}

/* This code example produces the following output:

Seismosaurus: up to 40 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.

Sort(dinosaurs, dinosaurSizes)

Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.
Coelophysis: up to 3 meters long.
Mamenchisaurus: up to 22 meters long.
Seismosaurus: up to 40 meters long.

Sort(dinosaurs, dinosaurSizes, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Caudipteryx: up to 1 meters long.
Cetiosaurus: up to 18 meters long.
Chasmosaurus: up to 5 meters long.

Sort(dinosaurs, dinosaurSizes, 3, 3, rc)

Seismosaurus: up to 40 meters long.
Mamenchisaurus: up to 22 meters long.
Coelophysis: up to 3 meters long.
Chasmosaurus: up to 5 meters long.
Cetiosaurus: up to 18 meters long.
Caudipteryx: up to 1 meters long.
 */

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.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<(Of <(T>)>)

BinarySearch

Other Resources

Performing Culture-Insensitive String Operations in Arrays