How To Implement IEnumerable<T> Interface In C# And VB.NET

Hello, According to MSDN, IEnumerable<T> Interface exposes the enumerator, which supports a simple iteration over a collection of a specified type. Collections such as List<T> implements this interface. For this demo, I created a simple class that implements IEnumerable<string>. You can use concrete types instead of string or ordinary data types. Presented are two classes in different languages (C# and VB.NET) that implements the interface. Notice that in VB.NET, the yield functionality is applied in an Iterator function.
C#.NET

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namespace IEnumerableExample { class Program { static void Main(string[] args) { MessagingApp myObject = new MessagingApp(); foreach (string item in myObject) { Console.WriteLine(item); } Console.ReadLine(); } } public class MessagingApp : IEnumerable<string> { string[] Messages = { "Test", "C#Program", "Testing" }; public IEnumerator<string> GetEnumerator() { foreach (var item in Messages) { if (item == null) { break; } yield return item; } } IEnumerator IEnumerable.GetEnumerator() { return this.GetEnumerator(); } } }

VB.NET

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Module Module1 Sub Main() Dim myObject As New MessagingApp For Each item As String In myObject Console.WriteLine(item) Next Console.ReadLine() End Sub Public Class MessagingApp Implements IEnumerable(Of String) Dim Messages As String() = {"Test", "VBProgram", "Hello"} Public Iterator Function GetEnumerator() As IEnumerator(Of String) _ Implements IEnumerable(Of String).GetEnumerator For Each item As String In Messages If item = Nothing Then Exit For End If Yield item Next End Function Private Function GetEnumerator1() As IEnumerator _ Implements IEnumerable.GetEnumerator Return Me.Messages.GetEnumerator() End Function End Class End Module

Output

References
Walkthrough: Implementing IEnumerable(Of T) in Visual Basic
IEnumerable Interface