HashSet<T>.SetEquals(IEnumerable<T>) Method

public:
 virtual bool SetEquals(System::Collections::Generic::IEnumerable<T> ^ other);

public:
 bool SetEquals(System::Collections::Generic::IEnumerable<T> ^ other);

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

[System.Security.SecurityCritical]
public bool SetEquals(System.Collections.Generic.IEnumerable<T> other);

abstract member SetEquals : seq<'T> -> bool
override this.SetEquals : seq<'T> -> bool

[<System.Security.SecurityCritical>]
member this.SetEquals : seq<'T> -> bool

[<System.Security.SecurityCritical>]
abstract member SetEquals : seq<'T> -> bool
override this.SetEquals : seq<'T> -> bool

Public Function SetEquals (other As IEnumerable(Of T)) As Boolean

Parameters

Returns

true if the HashSet<T> object is equal to other; otherwise, false.

Implements

Attributes

SecurityCriticalAttribute

Exceptions

Examples

The following example creates two disparate HashSet<T> objects and compares them to each another. Initially, the two sets are not equal, which is demonstrated by using the SetEquals method. The allNumbers HashSet<T> object is then modified, after which the sets are equal.

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
*/

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

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

 printfn " }"

let lowNumbers = HashSet<int>()
let allNumbers = HashSet<int>()

for i = 1 to 4 do
 lowNumbers.Add i |> ignore


for i = 0 to 9 do
 allNumbers.Add i |> ignore

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

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

printfn $"lowNumbers overlaps allNumbers: {lowNumbers.Overlaps allNumbers}"

printfn $"allNumbers and lowNumbers are equal sets: {allNumbers.SetEquals lowNumbers}"

// Show the results of sub/superset testing
printfn $"lowNumbers is a subset of allNumbers: {lowNumbers.IsSubsetOf allNumbers}"
printfn $"allNumbers is a superset of lowNumbers: {allNumbers.IsSupersetOf lowNumbers}"
printfn $"lowNumbers is a proper subset of allNumbers: {lowNumbers.IsProperSubsetOf allNumbers}"
printfn $"allNumbers is a proper superset of lowNumbers: {allNumbers.IsProperSupersetOf lowNumbers}"

// Modify allNumbers to remove numbers that are not in lowNumbers.
allNumbers.IntersectWith lowNumbers
printf $"allNumbers contains {allNumbers.Count} elements: "
displaySet allNumbers

printfn $"allNumbers and lowNumbers are equal sets: {allNumbers.SetEquals lowNumbers}"

// Show the results of sub/superset testing with the modified set.
printfn $"lowNumbers is a subset of allNumbers: {lowNumbers.IsSubsetOf allNumbers}"
printfn $"allNumbers is a superset of lowNumbers: {allNumbers.IsSupersetOf lowNumbers}"
printfn $"lowNumbers is a proper subset of allNumbers: {lowNumbers.IsProperSubsetOf allNumbers}"
printfn $"allNumbers is a proper superset of lowNumbers: {allNumbers.IsProperSupersetOf lowNumbers}"
// 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

Remarks

The SetEquals method ignores duplicate entries and the order of elements in the other parameter.

If the collection represented by other is a HashSet<T> collection with the same equality comparer as the current HashSet<T> object, this method is an O(n) operation. Otherwise, this method is an O(n + m) operation, where n is the number of elements in other and m is Count.