SortedList.GetKey(Int32) Method

Definition

Namespace:

System.Collections

Assembly:

System.Collections.NonGeneric.dll

Source:

SortedList.cs

Gets the key at the specified index of a SortedList object.

public:
 virtual System::Object ^ GetKey(int index);

public virtual object GetKey (int index);

abstract member GetKey : int -> obj
override this.GetKey : int -> obj

Public Overridable Function GetKey (index As Integer) As Object

Parameters

index

Int32

The zero-based index of the key to get.

Returns

Object

The key at the specified index of the SortedList object.

Exceptions

ArgumentOutOfRangeException

index is outside the range of valid indexes for the SortedList object.

Examples

The following code example shows how to get one or all the keys or values in a SortedList object.

#using <system.dll>

using namespace System;
using namespace System::Collections;
int main()
{
   
   // Creates and initializes a new SortedList.
   SortedList^ mySL = gcnew SortedList;
   mySL->Add( 1.3, "fox" );
   mySL->Add( 1.4, "jumps" );
   mySL->Add( 1.5, "over" );
   mySL->Add( 1.2, "brown" );
   mySL->Add( 1.1, "quick" );
   mySL->Add( 1.0, "The" );
   mySL->Add( 1.6, "the" );
   mySL->Add( 1.8, "dog" );
   mySL->Add( 1.7, "lazy" );
   
   // Gets the key and the value based on the index.
   int myIndex = 3;
   Console::WriteLine( "The key   at index {0} is {1}.", myIndex, mySL->GetKey( myIndex ) );
   Console::WriteLine( "The value at index {0} is {1}.", myIndex, mySL->GetByIndex( myIndex ) );
   
   // Gets the list of keys and the list of values.
   IList^ myKeyList = mySL->GetKeyList();
   IList^ myValueList = mySL->GetValueList();
   
   // Prints the keys in the first column and the values in the second column.
   Console::WriteLine( "\t-KEY-\t-VALUE-" );
   for ( int i = 0; i < mySL->Count; i++ )
      Console::WriteLine( "\t{0}\t{1}", myKeyList[ i ], myValueList[ i ] );
}

/*
This code produces the following output.

The key   at index 3 is 1.3.
The value at index 3 is fox.
        -KEY-   -VALUE-
        1       The
        1.1     quick
        1.2     brown
        1.3     fox
        1.4     jumps
        1.5     over
        1.6     the
        1.7     lazy
        1.8     dog
*/

using System;
using System.Collections;
public class SamplesSortedList  {

   public static void Main()  {

      // Creates and initializes a new SortedList.
      SortedList mySL = new SortedList();
      mySL.Add( 1.3, "fox" );
      mySL.Add( 1.4, "jumps" );
      mySL.Add( 1.5, "over" );
      mySL.Add( 1.2, "brown" );
      mySL.Add( 1.1, "quick" );
      mySL.Add( 1.0, "The" );
      mySL.Add( 1.6, "the" );
      mySL.Add( 1.8, "dog" );
      mySL.Add( 1.7, "lazy" );

      // Gets the key and the value based on the index.
      int myIndex=3;
      Console.WriteLine( "The key   at index {0} is {1}.", myIndex, mySL.GetKey( myIndex ) );
      Console.WriteLine( "The value at index {0} is {1}.", myIndex, mySL.GetByIndex( myIndex ) );

      // Gets the list of keys and the list of values.
      IList myKeyList = mySL.GetKeyList();
      IList myValueList = mySL.GetValueList();

      // Prints the keys in the first column and the values in the second column.
      Console.WriteLine( "\t-KEY-\t-VALUE-" );
      for ( int i = 0; i < mySL.Count; i++ )
         Console.WriteLine( "\t{0}\t{1}", myKeyList[i], myValueList[i] );
   }
}
/*
This code produces the following output.

The key   at index 3 is 1.3.
The value at index 3 is fox.
    -KEY-    -VALUE-
    1    The
    1.1    quick
    1.2    brown
    1.3    fox
    1.4    jumps
    1.5    over
    1.6    the
    1.7    lazy
    1.8    dog
*/

Imports System.Collections

Public Class SamplesSortedList
        
    Public Shared Sub Main()
        
        ' Creates and initializes a new SortedList.
        Dim mySL As New SortedList()
        mySL.Add(1.3, "fox")
        mySL.Add(1.4, "jumps")
        mySL.Add(1.5, "over")
        mySL.Add(1.2, "brown")
        mySL.Add(1.1, "quick")
        mySL.Add(1.0, "The")
        mySL.Add(1.6, "the")
        mySL.Add(1.8, "dog")
        mySL.Add(1.7, "lazy")
        
        ' Gets the key and the value based on the index.
        Dim myIndex As Integer = 3
        Console.WriteLine("The key   at index {0} is {1}.", myIndex, _
           mySL.GetKey(myIndex))
        Console.WriteLine("The value at index {0} is {1}.", myIndex, _
           mySL.GetByIndex(myIndex))
        
        ' Gets the list of keys and the list of values.
        Dim myKeyList As IList = mySL.GetKeyList()
        Dim myValueList As IList = mySL.GetValueList()
        
        ' Prints the keys in the first column and the values in the second column.
        Console.WriteLine(ControlChars.Tab & "-KEY-" & ControlChars.Tab & _
           "-VALUE-")
        Dim i As Integer
        For i = 0 To mySL.Count - 1
            Console.WriteLine(ControlChars.Tab & "{0}" & ControlChars.Tab & _
               "{1}", myKeyList(i), myValueList(i))
        Next i
    End Sub
End Class

' This code produces the following output.
' 
' The key   at index 3 is 1.3.
' The value at index 3 is fox.
'     -KEY-    -VALUE-
'     1    The
'     1.1    quick
'     1.2    brown
'     1.3    fox
'     1.4    jumps
'     1.5    over
'     1.6    the
'     1.7    lazy
'     1.8    dog

Remarks

The index sequence is based on the sort sequence. When an element is added, it is inserted into SortedList in the correct sort order, and the indexing adjusts accordingly. When an element is removed, the indexing also adjusts accordingly. Therefore, the index of a specific key/value pair might change as elements are added or removed from the SortedList object.

This method is an O(1) operation.