# HashSet<T>.Count 属性

## 定义

``````public:
property int Count { int get(); };``````
``public int Count { get; }``
``member this.Count : int``
``Public ReadOnly Property Count As Integer``

## 示例

``````HashSet<int> evenNumbers = new HashSet<int>();
HashSet<int> oddNumbers = new HashSet<int>();

for (int i = 0; i < 5; i++)
{
// Populate numbers with just even numbers.

// Populate oddNumbers with just odd numbers.
}

Console.Write("evenNumbers contains {0} elements: ", evenNumbers.Count);
DisplaySet(evenNumbers);

Console.Write("oddNumbers contains {0} elements: ", oddNumbers.Count);
DisplaySet(oddNumbers);

// Create a new HashSet populated with even numbers.
HashSet<int> numbers = new HashSet<int>(evenNumbers);
Console.WriteLine("numbers UnionWith oddNumbers...");
numbers.UnionWith(oddNumbers);

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:
* evenNumbers contains 5 elements: { 0 2 4 6 8 }
* oddNumbers contains 5 elements: { 1 3 5 7 9 }
* numbers UnionWith oddNumbers...
* numbers contains 10 elements: { 0 2 4 6 8 1 3 5 7 9 }
*/
``````
``````Imports System.Collections.Generic

Class Program

Shared Sub Main()

Dim evenNumbers As HashSet(Of Integer) = New HashSet(Of Integer)()
Dim oddNumbers As HashSet(Of Integer) = New HashSet(Of Integer)()

For i As Integer = 0 To 4

' Populate evenNumbers with only even numbers.

' Populate oddNumbers with only odd numbers.
Next i

Console.Write("evenNumbers contains {0} elements: ", evenNumbers.Count)
DisplaySet(evenNumbers)

Console.Write("oddNumbers contains {0} elements: ", oddNumbers.Count)
DisplaySet(oddNumbers)

' Create a new HashSet populated with even numbers.
Dim numbers As HashSet(Of Integer) = New HashSet(Of Integer)(evenNumbers)
Console.WriteLine("numbers UnionWith oddNumbers...")
numbers.UnionWith(oddNumbers)

Console.Write("numbers contains {0} elements: ", numbers.Count)
DisplaySet(numbers)
End Sub

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
' This example produces output similar to the following:
' evenNumbers contains 5 elements: { 0 2 4 6 8 }
' oddNumbers contains 5 elements: { 1 3 5 7 9 }
' numbers UnionWith oddNumbers...
' numbers contains 10 elements: { 0 2 4 6 8 1 3 5 7 9 }
``````

## 注解

HashSet<T> 对象的容量是对象可以容纳的元素数。The capacity of a HashSet<T> object is the number of elements that the object can hold. 当向对象添加元素时，HashSet<T> 对象的容量会自动增加。A HashSet<T> object's capacity automatically increases as elements are added to the object.