SortedList<TKey,TValue>.Keys Property

Definition

Namespace:

System.Collections.Generic

Assembly:

System.Collections.dll

Source:

SortedList.cs

Gets a collection containing the keys in the SortedList<TKey,TValue>, in sorted order.

public:
 property System::Collections::Generic::IList<TKey> ^ Keys { System::Collections::Generic::IList<TKey> ^ get(); };

public System.Collections.Generic.IList<TKey> Keys { get; }

member this.Keys : System.Collections.Generic.IList<'Key>

Public ReadOnly Property Keys As IList(Of TKey)

Property Value

IList<TKey>

A IList<T> containing the keys in the SortedList<TKey,TValue>.

Examples

The following code example shows how to enumerate the keys in the sorted list using the Keys property, and how to enumerate the keys and values in the sorted list.

The example also shows how to use the Keys property for efficient indexed retrieval of keys.

This code is part of a larger example that can be compiled and executed. See SortedList<TKey,TValue>.

// To get the keys alone, use the Keys property.
IList<String^>^ ilistKeys = openWith->Keys;

// The elements of the list are strongly typed with the
// type that was specified for the SortedList keys.
Console::WriteLine();
for each( String^ s in ilistKeys )
{
    Console::WriteLine("Key = {0}", s);
}

// The Keys property is an efficient way to retrieve
// keys by index.
Console::WriteLine("\nIndexed retrieval using the Keys " +
    "property: Keys[2] = {0}", openWith->Keys[2]);

// To get the keys alone, use the Keys property.
IList<string> ilistKeys = openWith.Keys;

// The elements of the list are strongly typed with the
// type that was specified for the SortedList keys.
Console.WriteLine();
foreach( string s in ilistKeys )
{
    Console.WriteLine("Key = {0}", s);
}

// The Keys property is an efficient way to retrieve
// keys by index.
Console.WriteLine("\nIndexed retrieval using the Keys " +
    "property: Keys[2] = {0}", openWith.Keys[2]);

' To get the keys alone, use the Keys property.
Dim ilistKeys As IList(Of String) = openWith.Keys

' The elements of the list are strongly typed with the
' type that was specified for the SortedList keys.
Console.WriteLine()
For Each s As String In ilistKeys 
    Console.WriteLine("Key = {0}", s)
Next s

' The Keys property is an efficient way to retrieve
' keys by index.
Console.WriteLine(vbLf & "Indexed retrieval using the " & _
    "Keys property: Keys(2) = {0}", openWith.Keys(2))

// To get the keys alone, use the Keys property.
let ilistKeys = openWith.Keys;

// The elements of the list are strongly typed with the
// type that was specified for the SortedList keys.
Console.WriteLine()
for s in ilistKeys do
    printfn $"Key = {s}"

// The Keys property is an efficient way to retrieve
// keys by index.
printf "\nIndexed retrieval using the Keys "
printfn $"property: Keys[2] = {openWith.Keys[2]}"

// When you use foreach to enumerate list elements,
// the elements are retrieved as KeyValuePair objects.
Console::WriteLine();
for each( KeyValuePair<String^, String^> kvp in openWith )
{
    Console::WriteLine("Key = {0}, Value = {1}",
        kvp.Key, kvp.Value);
}

// When you use foreach to enumerate list elements,
// the elements are retrieved as KeyValuePair objects.
Console.WriteLine();
foreach( KeyValuePair<string, string> kvp in openWith )
{
    Console.WriteLine("Key = {0}, Value = {1}",
        kvp.Key, kvp.Value);
}

' When you use foreach to enumerate list elements,
' the elements are retrieved as KeyValuePair objects.
Console.WriteLine()
For Each kvp As KeyValuePair(Of String, String) In openWith
    Console.WriteLine("Key = {0}, Value = {1}", _
        kvp.Key, kvp.Value)
Next kvp

// When you use foreach to enumerate list elements,
// the elements are retrieved as KeyValuePair objects.
Console.WriteLine()
for kvp in openWith do
    printfn $"Key = {kvp.Key}, Value = {kvp.Value}"

Remarks

The order of the keys in the IList<T> is the same as the order in the SortedList<TKey,TValue>.

The returned IList<T> is not a static copy; instead, the IList<T> refers back to the keys in the original SortedList<TKey,TValue>. Therefore, changes to the SortedList<TKey,TValue> continue to be reflected in the IList<T>.

The collection returned by the Keys property provides an efficient way to retrieve keys by index. It is not necessary to regenerate the list when the property is accessed, because the list is just a wrapper for the internal array of keys. The following code shows the use of the Keys property for indexed retrieval of keys from a sorted list of elements with string keys:

String^ v = mySortedList->Values[3];

string v = mySortedList.Values[3];

Dim v As String = mySortedList.Values(3)

let v = mySortedList.Values[3]

Retrieving the value of this property is an O(1) operation.

See also

• IList<T>
• Values