KeyValuePair<TKey,TValue> Struct
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Defines a key/value pair that can be set or retrieved.
generic <typename TKey, typename TValue>
public value class KeyValuePair
public struct KeyValuePair<TKey,TValue>
public readonly struct KeyValuePair<TKey,TValue>
[System.Serializable]
public struct KeyValuePair<TKey,TValue>
type KeyValuePair<'Key, 'Value> = struct
[<System.Serializable>]
type KeyValuePair<'Key, 'Value> = struct
Public Structure KeyValuePair(Of TKey, TValue)
- TKey
The type of the key.
- TValue
The type of the value.
- Inheritance
- Attributes
The following code example shows how to enumerate the keys and values in a dictionary, using the KeyValuePair<TKey,TValue> structure.
This code is part of a larger example provided for the Dictionary<TKey,TValue> class.
// When you use foreach to enumerate dictionary 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 dictionary 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 dictionary 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
The Dictionary<TKey,TValue>.Enumerator.Current property returns an instance of this type.
The foreach
statement of the C# language (for each
in C++, For Each
in Visual Basic) returns an object of the type of the elements in the collection. Since each element of a collection based on IDictionary<TKey,TValue> is a key/value pair, the element type is not the type of the key or the type of the value. Instead, the element type is KeyValuePair<TKey,TValue>. For example:
for each(KeyValuePair<String^, String^> kvp in myDictionary)
{
Console::WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}
foreach( KeyValuePair<string, string> kvp in myDictionary )
{
Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}
For Each kvp As KeyValuePair(Of String, String) In myDictionary
Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value)
Next kvp
The foreach
statement is a wrapper around the enumerator, which allows only reading from, not writing to, the collection.
Key |
Initializes a new instance of the KeyValuePair<TKey,TValue> structure with the specified key and value. |
Deconstruct(TKey, TValue) |
Deconstructs the current KeyValuePair<TKey,TValue>. |
To |
Returns a string representation of the KeyValuePair<TKey,TValue>, using the string representations of the key and value. |
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1 |
UWP | 10.0 |
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