HashSet<T> Konstruktorer

public:
 HashSet();

public HashSet();

Public Sub New ()

Exempel

I följande exempel visas hur du skapar och fyller i två HashSet<T> objekt. Det här exemplet är en del av ett större exempel för UnionWith metoden.

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);
}

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

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

Kommentarer

Kapaciteten för ett HashSet<T> objekt är antalet element som objektet kan innehålla. Ett HashSet<T> objekts kapacitet ökar automatiskt när element läggs till i objektet.

Den här konstruktorn är en O(1)-åtgärd.

public:
 HashSet(System::Collections::Generic::IEnumerable<T> ^ collection);

public HashSet(System.Collections.Generic.IEnumerable<T> collection);

new System.Collections.Generic.HashSet<'T> : seq<'T> -> System.Collections.Generic.HashSet<'T>

Public Sub New (collection As IEnumerable(Of T))

Parametrar

Undantag

Exempel

I följande exempel visas hur du skapar en HashSet<T> samling från en befintlig uppsättning. I det här exemplet skapas två uppsättningar med jämna eller udda heltal. Ett tredje HashSet<T> objekt skapas sedan från den jämna heltalsuppsättningen.

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 }

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

Kommentarer

Kapaciteten för ett HashSet<T> objekt är antalet element som objektet kan innehålla. Ett HashSet<T> objekts kapacitet ökar automatiskt när element läggs till i objektet.

Om collection innehåller dubbletter innehåller uppsättningen ett av varje unikt element. Inget undantag utlöses. Därför är storleken på den resulterande uppsättningen inte identisk med storleken på collection.

Den här konstruktorn är en O(n)-åtgärd, där n är antalet element i parametern collection .

public:
 HashSet(System::Collections::Generic::IEqualityComparer<T> ^ comparer);

public HashSet(System.Collections.Generic.IEqualityComparer<T> comparer);

new System.Collections.Generic.HashSet<'T> : System.Collections.Generic.IEqualityComparer<'T> -> System.Collections.Generic.HashSet<'T>

Public Sub New (comparer As IEqualityComparer(Of T))

Parametrar

Kommentarer

Kapaciteten för ett HashSet<T> objekt är antalet element som objektet kan innehålla. Ett HashSet<T> objekts kapacitet ökar automatiskt när element läggs till i objektet.

Den här konstruktorn är en O(1)-åtgärd.

public:
 HashSet(int capacity);

public HashSet(int capacity);

new System.Collections.Generic.HashSet<'T> : int -> System.Collections.Generic.HashSet<'T>

Public Sub New (capacity As Integer)

Parametrar

Kommentarer

Eftersom storleksändringen är relativt dyr (kräver omhashing) försöker detta minimera behovet av att ändra storlek genom att ange den ursprungliga kapaciteten baserat på värdet för capacity.

public:
 HashSet(System::Collections::Generic::IEnumerable<T> ^ collection, System::Collections::Generic::IEqualityComparer<T> ^ comparer);

public HashSet(System.Collections.Generic.IEnumerable<T> collection, System.Collections.Generic.IEqualityComparer<T> comparer);

new System.Collections.Generic.HashSet<'T> : seq<'T> * System.Collections.Generic.IEqualityComparer<'T> -> System.Collections.Generic.HashSet<'T>

Public Sub New (collection As IEnumerable(Of T), comparer As IEqualityComparer(Of T))

Parametrar

Undantag

Exempel

I följande exempel används en angiven IEqualityComparer<T> för att tillåta skiftlägesokänsliga jämförelser av elementen i en HashSet<T> samling fordonstyper.

HashSet<string> allVehicles = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
List<string> someVehicles = new List<string>();

someVehicles.Add("Planes");
someVehicles.Add("Trains");
someVehicles.Add("Automobiles");

// Add in the vehicles contained in the someVehicles list.
allVehicles.UnionWith(someVehicles);

Console.WriteLine("The current HashSet contains:\n");
foreach (string vehicle in allVehicles)
{
    Console.WriteLine(vehicle);
}

allVehicles.Add("Ships");
allVehicles.Add("Motorcycles");
allVehicles.Add("Rockets");
allVehicles.Add("Helicopters");
allVehicles.Add("Submarines");

Console.WriteLine("\nThe updated HashSet contains:\n");
foreach (string vehicle in allVehicles)
{
    Console.WriteLine(vehicle);
}

// Verify that the 'All Vehicles' set contains at least the vehicles in
// the 'Some Vehicles' list.
if (allVehicles.IsSupersetOf(someVehicles))
{
    Console.Write("\nThe 'All' vehicles set contains everything in ");
    Console.WriteLine("'Some' vechicles list.");
}

// Check for Rockets. Here the OrdinalIgnoreCase comparer will compare
// true for the mixed-case vehicle type.
if (allVehicles.Contains("roCKeTs"))
{
    Console.WriteLine("\nThe 'All' vehicles set contains 'roCKeTs'");
}

allVehicles.ExceptWith(someVehicles);
Console.WriteLine("\nThe excepted HashSet contains:\n");
foreach (string vehicle in allVehicles)
{
    Console.WriteLine(vehicle);
}

// Remove all the vehicles that are not 'super cool'.
allVehicles.RemoveWhere(isNotSuperCool);

Console.WriteLine("\nThe super cool vehicles are:\n");
foreach (string vehicle in allVehicles)
{
    Console.WriteLine(vehicle);
}

// Predicate to determine vehicle 'coolness'.
bool isNotSuperCool(string vehicle)
{
    bool superCool = (vehicle == "Helicopters") || (vehicle == "Motorcycles");

    return !superCool;
}

// The program writes the following output to the console.
//
// The current HashSet contains:
//
// Planes
// Trains
// Automobiles
//
// The updated HashSet contains:
//
// Planes
// Trains
// Automobiles
// Ships
// Motorcycles
// Rockets
// Helicopters
// Submarines
//
// The 'All' vehicles set contains everything in 'Some' vechicles list.
//
// The 'All' vehicles set contains 'roCKeTs'
//
// The excepted HashSet contains:
//
// Ships
// Motorcycles
// Rockets
// Helicopters
// Submarines
//
// The super cool vehicles are:
//
// Motorcycles
// Helicopters

let allVehicles = HashSet<string> StringComparer.OrdinalIgnoreCase
let someVehicles = ResizeArray()

someVehicles.Add "Planes"
someVehicles.Add "Trains"
someVehicles.Add "Automobiles"

// Add in the vehicles contained in the someVehicles list.
allVehicles.UnionWith someVehicles

printfn "The current HashSet contains:\n"

for vehicle in allVehicles do
    printfn $"{vehicle}"

allVehicles.Add "Ships" |> ignore
allVehicles.Add "Motorcycles" |> ignore
allVehicles.Add "Rockets" |> ignore
allVehicles.Add "Helicopters" |> ignore
allVehicles.Add "Submarines" |> ignore

printfn "\nThe updated HashSet contains:\n"

for vehicle in allVehicles do
    printfn $"{vehicle}"

// Verify that the 'All Vehicles' set contains at least the vehicles in
// the 'Some Vehicles' list.
if allVehicles.IsSupersetOf someVehicles then
    printfn "\nThe 'All' vehicles set contains everything in 'Some' vehicles list."

// Check for Rockets. Here the OrdinalIgnoreCase comparer will compare
// true for the mixed-case vehicle type.
if allVehicles.Contains "roCKeTs" then
    printfn "\nThe 'All' vehicles set contains 'roCKeTs'"

allVehicles.ExceptWith someVehicles
printfn "\nThe excepted HashSet contains:\n"

for vehicle in allVehicles do
    printfn $"{vehicle}"

// Predicate to determine vehicle 'coolness'.
let isNotSuperCool vehicle =
    let superCool = vehicle = "Helicopters" || vehicle = "Motorcycles"
    not superCool

// Remove all the vehicles that are not 'super cool'.
allVehicles.RemoveWhere isNotSuperCool |> ignore

printfn "\nThe super cool vehicles are:\n"

for vehicle in allVehicles do
    printfn $"{vehicle}"

// The program writes the following output to the console.
//
// The current HashSet contains:
//
// Planes
// Trains
// Automobiles
//
// The updated HashSet contains:
//
// Planes
// Trains
// Automobiles
// Ships
// Motorcycles
// Rockets
// Helicopters
// Submarines
//
// The 'All' vehicles set contains everything in 'Some' vehicles list.
//
// The 'All' vehicles set contains 'roCKeTs'
//
// The excepted HashSet contains:
//
// Ships
// Motorcycles
// Rockets
// Helicopters
// Submarines
//
// The super cool vehicles are:
//
// Motorcycles
// Helicopters

Imports System.Collections.Generic

Class Program
    Public Shared Sub Main()
        Dim allVehicles As New HashSet(Of String)(StringComparer.OrdinalIgnoreCase)
        Dim someVehicles As New List(Of String)()

        someVehicles.Add("Planes")
        someVehicles.Add("Trains")
        someVehicles.Add("Automobiles")

        ' Add in the vehicles contained in the someVehicles list.
        allVehicles.UnionWith(someVehicles)

        Console.WriteLine("The current HashSet contains:" + Environment.NewLine)
        For Each vehicle As String In allVehicles
            Console.WriteLine(vehicle)
        Next vehicle

        allVehicles.Add("Ships")
        allVehicles.Add("Motorcycles")
        allVehicles.Add("Rockets")
        allVehicles.Add("Helicopters")
        allVehicles.Add("Submarines")

        Console.WriteLine(Environment.NewLine + "The updated HashSet contains:" + Environment.NewLine)
        For Each vehicle As String In allVehicles
            Console.WriteLine(vehicle)
        Next vehicle

        ' Verify that the 'All Vehicles' set contains at least the vehicles in
        ' the 'Some Vehicles' list.
        If allVehicles.IsSupersetOf(someVehicles) Then
            Console.Write(Environment.NewLine + "The 'All' vehicles set contains everything in ")
            Console.WriteLine("'Some' vechicles list.")
        End If

        ' Check for Rockets. Here the OrdinalIgnoreCase comparer will compare
        ' True for the mixed-case vehicle type.
        If allVehicles.Contains("roCKeTs") Then
            Console.WriteLine(Environment.NewLine + "The 'All' vehicles set contains 'roCKeTs'")
        End If

        allVehicles.ExceptWith(someVehicles)
        Console.WriteLine(Environment.NewLine + "The excepted HashSet contains:" + Environment.NewLine)
        For Each vehicle As String In allVehicles
            Console.WriteLine(vehicle)
        Next vehicle

        ' Remove all the vehicles that are not 'super cool'.
        allVehicles.RemoveWhere(AddressOf isNotSuperCool)

        Console.WriteLine(Environment.NewLine + "The super cool vehicles are:" + Environment.NewLine)
        For Each vehicle As String In allVehicles
            Console.WriteLine(vehicle)
        Next vehicle
    End Sub

    ' Predicate to determine vehicle 'coolness'.
    Private Shared Function isNotSuperCool(vehicle As String) As Boolean
        Dim notSuperCool As Boolean = _
            (vehicle <> "Helicopters") And (vehicle <> "Motorcycles")

        Return notSuperCool
    End Function
End Class

'
' The program writes the following output to the console.
'
' The current HashSet contains:
'
' Planes
' Trains
' Automobiles
'
' The updated HashSet contains:
'
' Planes
' Trains
' Automobiles
' Ships
' Motorcycles
' Rockets
' Helicopters
' Submarines
'
' The 'All' vehicles set contains everything in 'Some' vechicles list.
'
' The 'All' vehicles set contains 'roCKeTs'
'
' The excepted HashSet contains:
'
' Ships
' Motorcycles
' Rockets
' Helicopters
' Submarines
'
' The super cool vehicles are:
'
' Motorcycles
' Helicopters

Kommentarer

Kapaciteten för ett HashSet<T> objekt är antalet element som objektet kan innehålla. Ett HashSet<T> objekts kapacitet ökar automatiskt när element läggs till i objektet.

Om collection innehåller dubbletter innehåller uppsättningen ett av varje unikt element. Inget undantag utlöses. Därför är storleken på den resulterande uppsättningen inte identisk med storleken på collection.

Den här konstruktorn är en O(n)-åtgärd, där n är antalet element i parametern collection .

public:
 HashSet(int capacity, System::Collections::Generic::IEqualityComparer<T> ^ comparer);

public HashSet(int capacity, System.Collections.Generic.IEqualityComparer<T> comparer);

new System.Collections.Generic.HashSet<'T> : int * System.Collections.Generic.IEqualityComparer<'T> -> System.Collections.Generic.HashSet<'T>

Public Sub New (capacity As Integer, comparer As IEqualityComparer(Of T))

Parametrar

Kommentarer

Eftersom storleksändringen är relativt dyr (kräver omhashing) försöker detta minimera behovet av att ändra storlek genom att ange den ursprungliga kapaciteten baserat på värdet för capacity.

protected:
 HashSet(System::Runtime::Serialization::SerializationInfo ^ info, System::Runtime::Serialization::StreamingContext context);

protected HashSet(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context);

new System.Collections.Generic.HashSet<'T> : System.Runtime.Serialization.SerializationInfo * System.Runtime.Serialization.StreamingContext -> System.Collections.Generic.HashSet<'T>

Protected Sub New (info As SerializationInfo, context As StreamingContext)

Parametrar

Kommentarer

Den här konstruktorn anropas under deserialiseringen för att återskapa ett objekt som överförs över en ström. Mer information finns i XML- och SOAP-serialisering.