Поделиться через


HashSet<T>.IsSubsetOf(IEnumerable<T>) Метод

Определение

Определяет, является ли объект HashSet<T> подмножеством указанной коллекции.

public:
 virtual bool IsSubsetOf(System::Collections::Generic::IEnumerable<T> ^ other);
public:
 bool IsSubsetOf(System::Collections::Generic::IEnumerable<T> ^ other);
public bool IsSubsetOf (System.Collections.Generic.IEnumerable<T> other);
[System.Security.SecurityCritical]
public bool IsSubsetOf (System.Collections.Generic.IEnumerable<T> other);
abstract member IsSubsetOf : seq<'T> -> bool
override this.IsSubsetOf : seq<'T> -> bool
[<System.Security.SecurityCritical>]
member this.IsSubsetOf : seq<'T> -> bool
[<System.Security.SecurityCritical>]
abstract member IsSubsetOf : seq<'T> -> bool
override this.IsSubsetOf : seq<'T> -> bool
Public Function IsSubsetOf (other As IEnumerable(Of T)) As Boolean

Параметры

other
IEnumerable<T>

Коллекция для сравнения с текущим объектом HashSet<T>.

Возвращаемое значение

Значение true, если объект HashSet<T> является подмножеством other; в противном случае — значение false.

Реализации

Атрибуты

Исключения

other имеет значение null.

Примеры

В следующем примере создаются два разрозненных HashSet<T> объекта и сравниваются друг с другом. В этом примере — это и подмножество, lowNumbers и подмножество allNumbers до тех allNumbers пор, пока изменяется с помощью IntersectWith метода , чтобы содержать только значения, которые присутствуют в обоих наборах. После того, как allNumbers и lowNumbers идентичны, lowNumbers по-прежнему является подмножеством , allNumbers но больше не является правильным подмножеством.

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

for (int i = 1; i < 5; i++)
{
    lowNumbers.Add(i);
}

for (int i = 0; i < 10; i++)
{
    allNumbers.Add(i);
}

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

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

Console.WriteLine("lowNumbers overlaps allNumbers: {0}",
    lowNumbers.Overlaps(allNumbers));

Console.WriteLine("allNumbers and lowNumbers are equal sets: {0}",
    allNumbers.SetEquals(lowNumbers));

// Show the results of sub/superset testing
Console.WriteLine("lowNumbers is a subset of allNumbers: {0}",
    lowNumbers.IsSubsetOf(allNumbers));
Console.WriteLine("allNumbers is a superset of lowNumbers: {0}",
    allNumbers.IsSupersetOf(lowNumbers));
Console.WriteLine("lowNumbers is a proper subset of allNumbers: {0}",
    lowNumbers.IsProperSubsetOf(allNumbers));
Console.WriteLine("allNumbers is a proper superset of lowNumbers: {0}",
    allNumbers.IsProperSupersetOf(lowNumbers));

// Modify allNumbers to remove numbers that are not in lowNumbers.
allNumbers.IntersectWith(lowNumbers);
Console.Write("allNumbers contains {0} elements: ", allNumbers.Count);
DisplaySet(allNumbers);

Console.WriteLine("allNumbers and lowNumbers are equal sets: {0}",
    allNumbers.SetEquals(lowNumbers));

// Show the results of sub/superset testing with the modified set.
Console.WriteLine("lowNumbers is a subset of allNumbers: {0}",
    lowNumbers.IsSubsetOf(allNumbers));
Console.WriteLine("allNumbers is a superset of lowNumbers: {0}",
    allNumbers.IsSupersetOf(lowNumbers));
Console.WriteLine("lowNumbers is a proper subset of allNumbers: {0}",
    lowNumbers.IsProperSubsetOf(allNumbers));
Console.WriteLine("allNumbers is a proper superset of lowNumbers: {0}",
    allNumbers.IsProperSupersetOf(lowNumbers));

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

/* This code example produces output similar to the following:
* lowNumbers contains 4 elements: { 1 2 3 4 }
* allNumbers contains 10 elements: { 0 1 2 3 4 5 6 7 8 9 }
* lowNumbers overlaps allNumbers: True
* allNumbers and lowNumbers are equal sets: False
* lowNumbers is a subset of allNumbers: True
* allNumbers is a superset of lowNumbers: True
* lowNumbers is a proper subset of allNumbers: True
* allNumbers is a proper superset of lowNumbers: True
* allNumbers contains 4 elements: { 1 2 3 4 }
* allNumbers and lowNumbers are equal sets: True
* lowNumbers is a subset of allNumbers: True
* allNumbers is a superset of lowNumbers: True
* lowNumbers is a proper subset of allNumbers: False
* allNumbers is a proper superset of lowNumbers: False
*/
Shared Sub Main()

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

    For i As Integer = 1 To 4
        lowNumbers.Add(i)
    Next i

    For i As Integer = 0 To 9
        allNumbers.Add(i)
    Next i


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

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

    Console.WriteLine("lowNumbers overlaps allNumbers: {0}", _
        lowNumbers.Overlaps(allNumbers))

    Console.WriteLine("allNumbers and lowNumbers are equal sets: {0}", _
        allNumbers.SetEquals(lowNumbers))

    ' Show the results of sub/superset testing
    Console.WriteLine("lowNumbers is a subset of allNumbers: {0}", _
        lowNumbers.IsSubsetOf(allNumbers))
    Console.WriteLine("allNumbers is a superset of lowNumbers: {0}", _
        allNumbers.IsSupersetOf(lowNumbers))
    Console.WriteLine("lowNumbers is a proper subset of allNumbers: {0}", _
        lowNumbers.IsProperSubsetOf(allNumbers))
    Console.WriteLine("allNumbers is a proper superset of lowNumbers: {0}", _
        allNumbers.IsProperSupersetOf(lowNumbers))

    ' Modify allNumbers to remove numbers that are not in lowNumbers.
    allNumbers.IntersectWith(lowNumbers)
    Console.Write("allNumbers contains {0} elements: ", allNumbers.Count)
    DisplaySet(allNumbers)

    Console.WriteLine("allNumbers and lowNumbers are equal sets: {0}", _
        allNumbers.SetEquals(lowNumbers))

    ' Show the results of sub/superset testing with the modified set.
    Console.WriteLine("lowNumbers is a subset of allNumbers: {0}", _
        lowNumbers.IsSubsetOf(allNumbers))
    Console.WriteLine("allNumbers is a superset of lowNumbers: {0}", _
        allNumbers.IsSupersetOf(lowNumbers))
    Console.WriteLine("lowNumbers is a proper subset of allNumbers: {0}", _
        lowNumbers.IsProperSubsetOf(allNumbers))
    Console.WriteLine("allNumbers is a proper superset of lowNumbers: {0}", _
        allNumbers.IsProperSupersetOf(lowNumbers))
End Sub
' This code example produces output similar to the following:
' lowNumbers contains 4 elements: { 1 2 3 4 }
' allNumbers contains 10 elements: { 0 1 2 3 4 5 6 7 8 9 }
' lowNumbers overlaps allNumbers: True
' allNumbers and lowNumbers are equal sets: False
' lowNumbers is a subset of allNumbers: True
' allNumbers is a superset of lowNumbers: True
' lowNumbers is a proper subset of allNumbers: True
' allNumbers is a proper superset of lowNumbers: True
' allNumbers contains 4 elements: { 1 2 3 4 }
' allNumbers and lowNumbers are equal sets: True
' lowNumbers is a subset of allNumbers: True
' allNumbers is a superset of lowNumbers: True
' lowNumbers is a proper subset of allNumbers: False
' allNumbers is a proper superset of lowNumbers: False

Комментарии

Пустой набор — это подмножество любой другой коллекции, включая пустой набор; Поэтому этот метод возвращает значение true , если коллекция, представленная текущим HashSet<T> объектом, пуста, даже если other параметр является пустым набором.

Этот метод всегда возвращает значение false , если Count больше числа элементов в other.

Если коллекция, представленная , является HashSet<T> коллекцией с тем же компаратором other равенства, что и текущий HashSet<T> объект, этот метод является операцией O(n). В противном случае этот метод является операцией O(n + m), где n — и mCount — количество элементов в .other

Применяется к