String.Concat(Of T) Method (IEnumerable(Of T))
Concatenates the members of an IEnumerable(Of T) implementation.
Assembly: mscorlib (in mscorlib.dll)
<ComVisibleAttribute(False)> Public Shared Function Concat(Of T) ( values As IEnumerable(Of T) ) As String
Parameters
- values
-
Type:
System.Collections.Generic.IEnumerable(Of T)
A collection object that implements the IEnumerable(Of T) interface.
Type Parameters
- T
The type of the members of values.
| Exception | Condition |
|---|---|
| ArgumentNullException | values is null. |
The method concatenates each object in values; it does not add any delimiters.
An Empty string is used in place of any null argument.
Concat(Of T)(IEnumerable(Of T)) is a convenience method that lets you concatenate each element in an IEnumerable(Of T) collection without first converting the elements to strings. It is particularly useful with Language-Integrated Query (LINQ) query expressions, as the example illustrates. The string representation of each object in the IEnumerable(Of T) collection is derived by calling that object's ToString method.
The following example defines a very simple Animal class that contains the name of an animal and the order to which it belongs. It then defines a List(Of T) object to contain a number of Animal objects. The Enumerable.Where(Of TSource) extension method is called to extract the Animal objects whose Order property equals "Rodent". The result is passed to the Concat(Of T)(IEnumerable(Of T)) method and displayed to the console.
Imports System.Collections.Generic Public Class Animal Public Kind As String Public Order As String Public Sub New(kind As String, order As String) Me.Kind = kind Me.Order = order End Sub Public Overrides Function ToString() As String Return Me.Kind End Function End Class Module Example Public Sub Main() Dim animals As New List(Of Animal) animals.Add(New Animal("Squirrel", "Rodent")) animals.Add(New Animal("Gray Wolf", "Carnivora")) animals.Add(New Animal("Capybara", "Rodent")) Dim output As String = String.Concat(animals.Where(Function(animal) _ animal.Order = "Rodent")) Console.WriteLine(output) End Sub End Module ' The example displays the following output: ' SquirrelCapybara
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 4.0
Windows Phone Silverlight
Available since 7.1
Windows Phone
Available since 8.1