HashSet<T>.Count プロパティ

public:
 property int Count { int get(); };

public int Count { get; }

member this.Count : int

Public ReadOnly Property Count As Integer

プロパティ値

セットに含まれる要素の数。

実装

例

次の例では、2 つの HashSet<T> オブジェクトを作成、設定、操作する方法を示します。 この例では、セットの内容と Count の両方がコンソールに表示されます。

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.
    evenNumbers.Add(i * 2);

    // Populate oddNumbers with just odd numbers.
    oddNumbers.Add((i * 2) + 1);
}

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> collection)
{
    Console.Write("{");
    foreach (int i in collection)
    {
        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 }
*/

let displaySet (collection: HashSet<int>) =
    printf "{"

    for i in collection do
        printf $" {i}"

    printfn " }"

let evenNumbers = HashSet<int>()
let oddNumbers = HashSet<int>()

for i = 0 to 4 do
    // Populate numbers with just even numbers.
    evenNumbers.Add(i * 2) |> ignore

    // Populate oddNumbers with just odd numbers.
    oddNumbers.Add(i * 2 + 1) |> ignore

printf $"evenNumbers contains {evenNumbers.Count} elements: "
displaySet evenNumbers

printf $"oddNumbers contains {oddNumbers.Count} elements: "
displaySet oddNumbers

// Create a new HashSet populated with even numbers.
let numbers = HashSet<int> evenNumbers
printfn "numbers UnionWith oddNumbers..."
numbers.UnionWith oddNumbers

printf $"numbers contains {numbers.Count} elements: "
displaySet numbers
// 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.
            evenNumbers.Add(i * 2)

            ' Populate oddNumbers with only odd numbers.
            oddNumbers.Add((i * 2) + 1)
        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 collection As HashSet(Of Integer))
        Console.Write("{")
        For Each i As Integer In collection
            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 }

注釈

HashSet<T> オブジェクトの容量は、オブジェクトが保持できる要素の数です。 HashSet<T> オブジェクトの容量は、要素がオブジェクトに追加されると自動的に増加します。

容量は常に Count以上です。 Count要素の追加中に容量を超えた場合、容量は前の容量の 2 倍を超える最初の素数に設定されます。

このプロパティの値の取得は O(1) 操作です。