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

定義

命名空間:

System.Collections.Generic

組件:

System.Collections.dll

來源:

HashSet.cs

判斷 HashSet<T> 物件是否為指定之集合的超集。

C#

public bool IsSupersetOf (System.Collections.Generic.IEnumerable<T> other);

參數

other

IEnumerable<T>

要與目前 HashSet<T> 物件比較的集合。

傳回

Boolean

如果 HashSet<T> 物件是 other 的超集，則為 true，否則為 false。

實作

IsSupersetOf(IEnumerable<T>) IsSupersetOf(IEnumerable<T>)

例外狀況

ArgumentNullException

other 為 null。

範例

下列範例會建立兩個不同的 HashSet<T> 物件，並將其彼此比較。 在此範例中，allNumbers是超集和適當的超集lowNumbers，直到使用 IntersectWith 方法修改為止allNumbers，只包含兩個集合中存在的值。 一旦 allNumbers 和 lowNumbers 相同，仍然是 的lowNumbers超集，allNumbers但不再是適當的超集。

C#

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
*/

備註

包括空集合在內的所有集合都是空集合的超集。 因此，即使目前的 HashSet<T> 對像是空的other，這個方法也會傳回 true 參數所表示的集合是空的。

如果 Count 小於 中的other項目數目，這個方法一律會false傳回 。

如果 所 other 表示的集合是 HashSet<T> 與目前 HashSet<T> 物件具有相同相等比較子的集合，則這個方法是 O (n) 運算。 否則，這個方法是 O (n + m) 作業，其中 n 是和中的 othermCount項目數目。

適用於