Enumerable.Union Método
Definição
Produz a união de conjunto de duas sequências.Produces the set union of two sequences.
Sobrecargas
| Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) |
Produz a união de conjunto de duas sequências usando o comparador de igualdade padrão.Produces the set union of two sequences by using the default equality comparer. |
| Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
Produz a união de conjunto de duas sequências usando o IEqualityComparer<T> especificado.Produces the set union of two sequences by using a specified IEqualityComparer<T>. |
Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)
Produz a união de conjunto de duas sequências usando o comparador de igualdade padrão.Produces the set union of two sequences by using the default equality comparer.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static System::Collections::Generic::IEnumerable<TSource> ^ Union(System::Collections::Generic::IEnumerable<TSource> ^ first, System::Collections::Generic::IEnumerable<TSource> ^ second);
public static System.Collections.Generic.IEnumerable<TSource> Union<TSource> (this System.Collections.Generic.IEnumerable<TSource> first, System.Collections.Generic.IEnumerable<TSource> second);
static member Union : seq<'Source> * seq<'Source> -> seq<'Source>
<Extension()>
Public Function Union(Of TSource) (first As IEnumerable(Of TSource), second As IEnumerable(Of TSource)) As IEnumerable(Of TSource)
Parâmetros de tipo
- TSource
O tipo dos elementos das sequências de entrada.The type of the elements of the input sequences.
Parâmetros
- first
- IEnumerable<TSource>
Um IEnumerable<T> cujos elementos distintos formam o primeiro conjunto da união.An IEnumerable<T> whose distinct elements form the first set for the union.
- second
- IEnumerable<TSource>
Um IEnumerable<T> cujos elementos distintos formam o segundo conjunto da união.An IEnumerable<T> whose distinct elements form the second set for the union.
Retornos
- IEnumerable<TSource>
Um IEnumerable<T> que contém os elementos de ambas as sequências de entrada, excluindo as duplicatas.An IEnumerable<T> that contains the elements from both input sequences, excluding duplicates.
Exceções
first ou second é null.first or second is null.
Exemplos
O exemplo de código a seguir demonstra como usar Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) o para obter a União de duas sequências de inteiros.The following code example demonstrates how to use Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) to obtain the union of two sequences of integers.
int[] ints1 = { 5, 3, 9, 7, 5, 9, 3, 7 };
int[] ints2 = { 8, 3, 6, 4, 4, 9, 1, 0 };
IEnumerable<int> union = ints1.Union(ints2);
foreach (int num in union)
{
Console.Write("{0} ", num);
}
/*
This code produces the following output:
5 3 9 7 8 6 4 1 0
*/
' Create two arrays of integer values.
Dim ints1() As Integer = {5, 3, 9, 7, 5, 9, 3, 7}
Dim ints2() As Integer = {8, 3, 6, 4, 4, 9, 1, 0}
' Get the set union of the two arrays.
Dim union As IEnumerable(Of Integer) = ints1.Union(ints2)
' Display the resulting set's values.
Dim output As New System.Text.StringBuilder
For Each num As Integer In union
output.AppendLine(num & " ")
Next
Console.WriteLine(output.ToString())
' This code produces the following output:
'
' 5
' 3
' 9
' 7
' 8
' 6
' 4
' 1
' 0
Se você quiser comparar sequências de objetos de algum tipo de dados personalizado, precisará implementar a IEquatable<T> interface genérica em uma classe auxiliar.If you want to compare sequences of objects of some custom data type, you have to implement the IEquatable<T> generic interface in a helper class. O exemplo de código a seguir mostra como implementar essa interface em um tipo de dados personalizado e substituir GetHashCode e Equals métodos.The following code example shows how to implement this interface in a custom data type and override GetHashCode and Equals methods.
public class ProductA: IEquatable<ProductA>
{
public string Name { get; set; }
public int Code { get; set; }
public bool Equals(ProductA other)
{
if (other is null)
return false;
return this.Name == other.Name && this.Code == other.Code;
}
public override bool Equals(object obj) => Equals(obj as ProductA);
public override int GetHashCode() => (Name, Code).GetHashCode();
}
Public Class ProductA
Inherits IEquatable(Of ProductA)
Public Property Name As String
Public Property Code As Integer
Public Function Equals(ByVal other As ProductA) As Boolean
If other Is Nothing Then Return False
Return Me.Name = other.Name AndAlso Me.Code = other.Code
End Function
Public Overrides Function Equals(ByVal obj As Object) As Boolean
Return Equals(TryCast(obj, ProductA))
End Function
Public Overrides Function GetHashCode() As Integer
Return (Name, Code).GetHashCode()
End Function
End Class
Depois de implementar essa interface, você pode usar sequências de ProductA objetos no Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) método, conforme mostrado no exemplo a seguir:After you implement this interface, you can use sequences of ProductA objects in the Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) method, as shown in the following example:
ProductA[] store1 = { new ProductA { Name = "apple", Code = 9 },
new ProductA { Name = "orange", Code = 4 } };
ProductA[] store2 = { new ProductA { Name = "apple", Code = 9 },
new ProductA { Name = "lemon", Code = 12 } };
Dim store1() As ProductA =
{New Product With {.Name = "apple", .Code = 9},
New Product With {.Name = "orange", .Code = 4}}
Dim store2() As ProductA =
{New Product With {.Name = "apple", .Code = 9},
New Product With {.Name = "lemon", .Code = 12}}
//Get the products from the both arrays
//excluding duplicates.
IEnumerable<ProductA> union =
store1.Union(store2);
foreach (var product in union)
Console.WriteLine(product.Name + " " + product.Code);
/*
This code produces the following output:
apple 9
orange 4
lemon 12
*/
' Get the products from the both arrays
' excluding duplicates.
Dim union = store1.Union(store2)
For Each product In union
Console.WriteLine(product.Name & " " & product.Code)
Next
' This code produces the following output:
'
' apple 9
' orange 4
' lemon 12
'
Comentários
Esse método é implementado usando a execução adiada.This method is implemented by using deferred execution. O valor de retorno imediato é um objeto que armazena todas as informações necessárias para executar a ação.The immediate return value is an object that stores all the information that is required to perform the action. A consulta representada por esse método não é executada até que o objeto seja enumerado chamando o GetEnumerator método diretamente ou usando o foreach no Visual C# ou For Each no Visual Basic.The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.
Esse método exclui duplicatas do conjunto de retorno.This method excludes duplicates from the return set. Esse é um comportamento diferente para o Concat método, que retorna todos os elementos nas sequências de entrada, incluindo duplicatas.This is different behavior to the Concat method, which returns all the elements in the input sequences including duplicates.
O comparador de igualdade padrão, Default , é usado para comparar valores dos tipos que implementam a IEqualityComparer<T> interface genérica.The default equality comparer, Default, is used to compare values of the types that implement the IEqualityComparer<T> generic interface. Para comparar um tipo de dados personalizado, você precisa implementar essa interface e fornecer seus próprios GetHashCode Equals métodos e para o tipo.To compare a custom data type, you need to implement this interface and provide your own GetHashCode and Equals methods for the type.
Quando o objeto retornado por esse método é enumerado, Union enumera first e second nessa ordem e produz cada elemento que ainda não foi produzido.When the object returned by this method is enumerated, Union enumerates first and second in that order and yields each element that has not already been yielded.
Aplica-se a
Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)
Produz a união de conjunto de duas sequências usando o IEqualityComparer<T> especificado.Produces the set union of two sequences by using a specified IEqualityComparer<T>.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static System::Collections::Generic::IEnumerable<TSource> ^ Union(System::Collections::Generic::IEnumerable<TSource> ^ first, System::Collections::Generic::IEnumerable<TSource> ^ second, System::Collections::Generic::IEqualityComparer<TSource> ^ comparer);
public static System.Collections.Generic.IEnumerable<TSource> Union<TSource> (this System.Collections.Generic.IEnumerable<TSource> first, System.Collections.Generic.IEnumerable<TSource> second, System.Collections.Generic.IEqualityComparer<TSource> comparer);
public static System.Collections.Generic.IEnumerable<TSource> Union<TSource> (this System.Collections.Generic.IEnumerable<TSource> first, System.Collections.Generic.IEnumerable<TSource> second, System.Collections.Generic.IEqualityComparer<TSource>? comparer);
static member Union : seq<'Source> * seq<'Source> * System.Collections.Generic.IEqualityComparer<'Source> -> seq<'Source>
<Extension()>
Public Function Union(Of TSource) (first As IEnumerable(Of TSource), second As IEnumerable(Of TSource), comparer As IEqualityComparer(Of TSource)) As IEnumerable(Of TSource)
Parâmetros de tipo
- TSource
O tipo dos elementos das sequências de entrada.The type of the elements of the input sequences.
Parâmetros
- first
- IEnumerable<TSource>
Um IEnumerable<T> cujos elementos distintos formam o primeiro conjunto da união.An IEnumerable<T> whose distinct elements form the first set for the union.
- second
- IEnumerable<TSource>
Um IEnumerable<T> cujos elementos distintos formam o segundo conjunto da união.An IEnumerable<T> whose distinct elements form the second set for the union.
- comparer
- IEqualityComparer<TSource>
O IEqualityComparer<T> para comparar valores.The IEqualityComparer<T> to compare values.
Retornos
- IEnumerable<TSource>
Um IEnumerable<T> que contém os elementos de ambas as sequências de entrada, excluindo as duplicatas.An IEnumerable<T> that contains the elements from both input sequences, excluding duplicates.
Exceções
first ou second é null.first or second is null.
Exemplos
O exemplo a seguir mostra como implementar um comparador de igualdade que pode ser usado no Union método.The following example shows how to implement an equality comparer that can be used in the Union method.
public class Product
{
public string Name { get; set; }
public int Code { get; set; }
}
// Custom comparer for the Product class
class ProductComparer : IEqualityComparer<Product>
{
// Products are equal if their names and product numbers are equal.
public bool Equals(Product x, Product y)
{
//Check whether the compared objects reference the same data.
if (Object.ReferenceEquals(x, y)) return true;
//Check whether any of the compared objects is null.
if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))
return false;
//Check whether the products' properties are equal.
return x.Code == y.Code && x.Name == y.Name;
}
// If Equals() returns true for a pair of objects
// then GetHashCode() must return the same value for these objects.
public int GetHashCode(Product product)
{
//Check whether the object is null
if (Object.ReferenceEquals(product, null)) return 0;
//Get hash code for the Name field if it is not null.
int hashProductName = product.Name == null ? 0 : product.Name.GetHashCode();
//Get hash code for the Code field.
int hashProductCode = product.Code.GetHashCode();
//Calculate the hash code for the product.
return hashProductName ^ hashProductCode;
}
}
Public Class Product
Public Property Name As String
Public Property Code As Integer
End Class
' Custom comparer for the Product class
Public Class ProductComparer
Implements IEqualityComparer(Of Product)
Public Function Equals1(
ByVal x As Product,
ByVal y As Product
) As Boolean Implements IEqualityComparer(Of Product).Equals
' Check whether the compared objects reference the same data.
If x Is y Then Return True
'Check whether any of the compared objects is null.
If x Is Nothing OrElse y Is Nothing Then Return False
' Check whether the products' properties are equal.
Return (x.Code = y.Code) AndAlso (x.Name = y.Name)
End Function
Public Function GetHashCode1(
ByVal product As Product
) As Integer Implements IEqualityComparer(Of Product).GetHashCode
' Check whether the object is null.
If product Is Nothing Then Return 0
' Get hash code for the Name field if it is not null.
Dim hashProductName =
If(product.Name Is Nothing, 0, product.Name.GetHashCode())
' Get hash code for the Code field.
Dim hashProductCode = product.Code.GetHashCode()
' Calculate the hash code for the product.
Return hashProductName Xor hashProductCode
End Function
End Class
Depois de implementar esse comparador, você pode usar sequências de Product objetos no Union método, conforme mostrado no exemplo a seguir:After you implement this comparer, you can use sequences of Product objects in the Union method, as shown in the following example:
Product[] store1 = { new Product { Name = "apple", Code = 9 },
new Product { Name = "orange", Code = 4 } };
Product[] store2 = { new Product { Name = "apple", Code = 9 },
new Product { Name = "lemon", Code = 12 } };
Dim store1() As Product =
{New Product With {.Name = "apple", .Code = 9},
New Product With {.Name = "orange", .Code = 4}}
Dim store2() As Product =
{New Product With {.Name = "apple", .Code = 9},
New Product With {.Name = "lemon", .Code = 12}}
//Get the products from the both arrays
//excluding duplicates.
IEnumerable<Product> union =
store1.Union(store2, new ProductComparer());
foreach (var product in union)
Console.WriteLine(product.Name + " " + product.Code);
/*
This code produces the following output:
apple 9
orange 4
lemon 12
*/
' Get the products from the both arrays
' excluding duplicates.
Dim union = store1.Union(store2, New ProductComparer())
For Each product In union
Console.WriteLine(product.Name & " " & product.Code)
Next
' This code produces the following output:
'
' apple 9
' orange 4
' lemon 12
'
Comentários
Esse método é implementado usando a execução adiada.This method is implemented by using deferred execution. O valor de retorno imediato é um objeto que armazena todas as informações necessárias para executar a ação.The immediate return value is an object that stores all the information that is required to perform the action. A consulta representada por esse método não é executada até que o objeto seja enumerado chamando o GetEnumerator método diretamente ou usando o foreach no Visual C# ou For Each no Visual Basic.The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.
Se comparer for null , o comparador de igualdade padrão, Default , será usado para comparar valores.If comparer is null, the default equality comparer, Default, is used to compare values.
Quando o objeto retornado por esse método é enumerado, Union enumera first e second nessa ordem e produz cada elemento que ainda não foi produzido.When the object returned by this method is enumerated, Union enumerates first and second in that order and yields each element that has not already been yielded.
O Concat método difere do Union método porque o Concat método retorna todos os elementos nas sequências de entrada, incluindo duplicatas, enquanto Union retorna apenas valores exclusivos.The Concat method differs from the Union method because the Concat method returns all the elements in the input sequences including duplicates, whereas Union returns only unique values.