Csharp/C Sharp by API/System.Collections/IEnumerable

IEnumerable.DescendantNodes()

  
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XDocument xDocument = new XDocument(
         new XElement("Books",
           new XElement("Book",
            new XAttribute("type", "Author"),
           new XComment("This is a new author."),
            new XElement("FirstName", "A"),
           new XElement("LastName", "B")),
           new XElement("Book",
            new XAttribute("type", "Author"),
           new XElement("FirstName", "C"),
           new XElement("LastName", "D"))));
        IEnumerable<XElement> elements = xDocument.Element("Books").Elements("Book");
        foreach (XElement element in elements) {
            Console.WriteLine("Source element: {0} : value = {1}", element.Name, element.Value);
        }
        foreach (XNode node in elements.DescendantNodes()) {
            Console.WriteLine("Descendant node: {0}", node);
        }
    }
}

IEnumerable.DescendantNodesAndSelf()

  
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XDocument xDocument = new XDocument(
         new XElement("Books",
           new XElement("Book",
            new XAttribute("type", "Author"),
           new XComment("This is a new author."),
            new XElement("FirstName", "A"),
           new XElement("LastName", "B")),
           new XElement("Book",
            new XAttribute("type", "Author"),
           new XElement("FirstName", "C"),
           new XElement("LastName", "D"))));
        IEnumerable<XElement> elements = xDocument.Element("Books").Elements("Book");
        foreach (XElement element in elements) {
            Console.WriteLine("Source element: {0} : value = {1}", element.Name, element.Value);
        }
        foreach (XNode node in elements.DescendantNodesAndSelf()) {
            Console.WriteLine("Descendant node: {0}", node);
        }
    }
}

IEnumerable.DescendantsAndSelf(String tagName)

  
using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XDocument xDocument = new XDocument(
         new XElement("Books",
           new XElement("Book",
            new XAttribute("type", "Author"),
           new XComment("This is a new author."),
            new XElement("FirstName", "A"),
           new XElement("LastName", "B")),
           new XElement("Book",
            new XAttribute("type", "Author"),
           new XElement("FirstName", "C"),
           new XElement("LastName", "D"))));
        IEnumerable<XElement> elements = xDocument.Element("Books").Elements("Book");
        foreach (XElement element in elements) {
            Console.WriteLine("Source element: {0} : value = {1}", element.Name, element.Value);
        }
        foreach (XElement element in elements.DescendantsAndSelf("LastName")) {
            Console.WriteLine("Descendant element: {0}", element);
        }
    }
}

IEnumerable.GetEnumerator()

  
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;
public class MainClass
{
    public static void Main()
    {
        IEnumerable<string> enumerable = new string[] { "A", "B", "C" };
        foreach (string s in enumerable)
            Console.WriteLine(s);
        IEnumerator<string> enumerator = enumerable.GetEnumerator();
        while (enumerator.MoveNext())
        {
            string s = enumerator.Current;
            Console.WriteLine(s);
        }
    }
}

implements IEnumerable

  
using System;
using System.Collections;
using System.Collections.Generic;
public class MyColl<T> : IEnumerable<T> {
    private T[] items;
    public MyColl( T[] items ) {
        this.items = items;
    }
    public IEnumerator<T> GetEnumerator() {
        foreach( T item in items ) {
            yield return item;
        }
    }
    IEnumerator IEnumerable.GetEnumerator() {
        return GetEnumerator();
    }
}
public class Test {
    static void Main() {
        MyColl<int> integers = new MyColl<int>( new int[] {1, 2, 3, 4} );
        foreach( int n in integers ) {
            Console.WriteLine( n );
        }
    }
}