HashSet<T>.TrimExcess Method
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
| TrimExcess() |
Sets the capacity of a HashSet<T> object to the actual number of elements it contains, rounded up to a nearby, implementation-specific value. |
| TrimExcess(Int32) |
Sets the capacity of a HashSet<T> object to the specified number of entries, rounded up to a nearby, implementation-specific value. |
- Source:
- HashSet.cs
- Source:
- HashSet.cs
- Source:
- HashSet.cs
Sets the capacity of a HashSet<T> object to the actual number of elements it contains, rounded up to a nearby, implementation-specific value.
public:
void TrimExcess();public void TrimExcess();member this.TrimExcess : unit -> unitPublic Sub TrimExcess ()Examples
The following example creates and populates a HashSet<T> collection, and then clears the collection and releases the memory referenced by it.
HashSet<int> Numbers = new HashSet<int>();
for (int i = 0; i < 10; i++)
{
Numbers.Add(i);
}
Console.Write("Numbers contains {0} elements: ", Numbers.Count);
DisplaySet(Numbers);
Numbers.Clear();
Numbers.TrimExcess();
Console.Write("Numbers contains {0} elements: ", Numbers.Count);
DisplaySet(Numbers);
void DisplaySet(HashSet<int> set)
{
Console.Write("{");
foreach (int i in set)
{
Console.Write(" {0}", i);
}
Console.WriteLine(" }");
}
/* This example produces output similar to the following:
* Numbers contains 10 elements: { 0 1 2 3 4 5 6 7 8 9 }
* Numbers contains 0 elements: { }
*/
let displaySet (set: HashSet<int>) =
printf "{"
for i in set do
printf $" {i}"
printfn " }"
// This example produces output similar to the following:
// Numbers contains 10 elements: { 0 1 2 3 4 5 6 7 8 9 }
// Numbers contains 0 elements: { }
let numbers = HashSet<int>()
for i = 0 to 9 do
numbers.Add i |> ignore
printf $"Numbers contains {numbers.Count} elements: "
displaySet numbers
numbers.Clear()
numbers.TrimExcess()
printf $"Numbers contains {numbers.Count} elements: "
displaySet numbers
Imports System.Collections.Generic
Class Program
Shared Sub Main()
Dim Numbers As HashSet(Of Integer) = New HashSet(Of Integer)()
For i As Integer = 0 To 9
Numbers.Add(i)
Next i
Console.Write("Numbers contains {0} elements: ", Numbers.Count)
DisplaySet(Numbers)
Numbers.Clear()
Numbers.TrimExcess()
Console.Write("Numbers contains {0} elements: ", Numbers.Count)
DisplaySet(Numbers)
End Sub
' This code example produces output similar to the following:
' Numbers contains 10 elements: { 0 1 2 3 4 5 6 7 8 9 }
' Numbers contains 0 elements: { }
Private Shared Sub DisplaySet(ByVal coll As HashSet(Of Integer))
Console.Write("{")
For Each i As Integer In coll
Console.Write(" {0}", i)
Next i
Console.WriteLine(" }")
End Sub
End Class
Remarks
You can use the TrimExcess method to minimize a HashSet<T> object's memory overhead once it is known that no new elements will be added. To completely clear a HashSet<T> object and release all memory referenced by it, call this method after calling the Clear method.
This method is an O(n) operation, where n is Count.
Applies to
.NET 10 и други версии
| Продукт | Версии |
|---|---|
| .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, 10 |
| .NET Framework | 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, 1.6, 2.0, 2.1 |
| UWP | 10.0 |
- Source:
- HashSet.cs
Sets the capacity of a HashSet<T> object to the specified number of entries, rounded up to a nearby, implementation-specific value.
public:
void TrimExcess(int capacity);public void TrimExcess(int capacity);member this.TrimExcess : int -> unitPublic Sub TrimExcess (capacity As Integer)Parameters
- capacity
- Int32
The new capacity.
Exceptions
The specified capacity is lower than the count of entries.
Applies to
.NET 10 и .NET 9
| Продукт | Версии |
|---|---|
| .NET | 9, 10 |
Обратна връзка за .NET
.NET е проект с отворен код. Изберете връзка, за да предоставите обратна връзка: