HashSet<T>.ExceptWith(IEnumerable<T>) 方法

定義

命名空間:

System.Collections.Generic

組件:

System.Collections.dll

來源:

HashSet.cs

將指定集合中的所有項目從目前的 HashSet<T> 物件中移除。

public:
 virtual void ExceptWith(System::Collections::Generic::IEnumerable<T> ^ other);

public void ExceptWith (System.Collections.Generic.IEnumerable<T> other);

abstract member ExceptWith : seq<'T> -> unit
override this.ExceptWith : seq<'T> -> unit

Public Sub ExceptWith (other As IEnumerable(Of T))

參數

other

IEnumerable<T>

要從 HashSet<T> 物件中移除的項目集合。

實作

ExceptWith(IEnumerable<T>)

例外狀況

ArgumentNullException

other 為 null。

範例

下列範例會建立兩 HashSet<T> 個具有重疊數據集的集合。 然後使用 方法，從較大的集合 ExceptWith 中移除較低的值範圍。

static void Main()
{
    HashSet<int>^ lowNumbers = gcnew HashSet<int>();
    HashSet<int>^ highNumbers = gcnew HashSet<int>();

    for (int i = 0; i < 6; i++)
    {
        lowNumbers->Add(i);
    }

    for (int i = 3; i < 10; i++)
    {
        highNumbers->Add(i);
    }

    Console::Write("lowNumbers contains {0} elements: ", lowNumbers->Count);
    DisplaySet(lowNumbers);

    Console::Write("highNumbers contains {0} elements: ", highNumbers->Count);
    DisplaySet(highNumbers);

    Console::WriteLine("highNumbers ExceptWith lowNumbers...");
    highNumbers->ExceptWith(lowNumbers);

    Console::Write("highNumbers contains {0} elements: ", highNumbers->Count);
    DisplaySet(highNumbers);
}
/* This example provides output similar to the following:
 * lowNumbers contains 6 elements: { 0 1 2 3 4 5 }
 * highNumbers contains 7 elements: { 3 4 5 6 7 8 9 }
 * highNumbers ExceptWith lowNumbers...
 * highNumbers contains 4 elements: { 6 7 8 9 }
 */

HashSet<int> lowNumbers = new HashSet<int>();
HashSet<int> highNumbers = new HashSet<int>();

for (int i = 0; i < 6; i++)
{
    lowNumbers.Add(i);
}

for (int i = 3; i < 10; i++)
{
    highNumbers.Add(i);
}

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

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

Console.WriteLine("highNumbers ExceptWith lowNumbers...");
highNumbers.ExceptWith(lowNumbers);

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

void DisplaySet(HashSet<int> set)
{
    Console.Write("{");
    foreach (int i in set)
    {
        Console.Write(" {0}", i);
    }
    Console.WriteLine(" }");
}

/* This example provides output similar to the following:
* lowNumbers contains 6 elements: { 0 1 2 3 4 5 }
* highNumbers contains 7 elements: { 3 4 5 6 7 8 9 }
* highNumbers ExceptWith lowNumbers...
* highNumbers contains 4 elements: { 6 7 8 9 }
*/

Shared Sub Main()

    Dim lowNumbers As HashSet(Of Integer) = New HashSet(Of Integer)()
    Dim highNumbers As HashSet(Of Integer) = New HashSet(Of Integer)()

    For i As Integer = 0 To 5
        lowNumbers.Add(i)
    Next i

    For i As Integer = 3 To 9
        highNumbers.Add(i)
    Next i

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

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

    Console.WriteLine("highNumbers ExceptWith lowNumbers...")
    highNumbers.ExceptWith(lowNumbers)

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

End Sub
' This example provides output similar to the following:
' lowNumbers contains 6 elements: { 0 1 2 3 4 5 }
' highNumbers contains 7 elements: { 3 4 5 6 7 8 9 }
' highNumbers ExceptWith lowNumbers...
' highNumbers contains 4 elements: { 6 7 8 9 }

備註

方法 ExceptWith 相當於數學集減法。

這個方法是 O (n) 作業，其中 n 是 參數中的 other 元素數目。