// CStringCollection.cs.
// http://svc.luckstar.com.tw/CodeHelper/cs/KeyWord/StringCollection.txt
// CodeHelper for StringCollection.

// 2017-03-19, honda@luckstar.com.tw, Create Based on CollectionSample.sln.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
// add
using System.Collections.Specialized;

namespace ConsoleBase
{
    public class CStringCollection
    {
        public void Run()
        {
            // Create and initializes a new StringCollection.
            StringCollection list1 = new StringCollection();

            // Add a range of elements from an array to the end of the StringCollection.
            String[] sa1 = new String[] { "RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED" };
            list1.AddRange(sa1);

            // Display the contents of the collection using foreach. This is the preferred method.
            Console.WriteLine("Displays the elements using foreach:");
            PrintForEach(list1);

            // Display the contents of the collection using the enumerator.
            Console.WriteLine("Displays the elements using the IEnumerator:");
            PrintEnumerating(list1);

            // Display the contents of the collection using the Count and Item properties.
            Console.WriteLine("Displays the elements using the Count and Item properties:");
            PrintCountAndItem(list1);

            // Add one element to the end of the StringCollection and insert another at index 3.
            list1.Add("* white");
            list1.Insert(3, "* gray");

            Console.WriteLine("After adding \"* white\" to the end and inserting \"* gray\" at index 3:");
            PrintForEach(list1);

            // Remove one element from the StringCollection.
            list1.Remove("yellow");

            Console.WriteLine("After removing \"yellow\":");
            PrintForEach(list1);

            // Remove all occurrences of a value from the StringCollection.
            int i = list1.IndexOf("RED");
            while (i > -1)
            {
                list1.RemoveAt(i);
                i = list1.IndexOf("RED");
            }

            // Verify that all occurrences of "RED" are gone.
            if (list1.Contains("RED"))
                Console.WriteLine("*** The collection still contains \"RED\".");

            Console.WriteLine("After removing all occurrences of \"RED\":");
            PrintForEach(list1);

            // Copy the collection to a new array starting at index 0.
            String[] myArr2 = new String[list1.Count];
            list1.CopyTo(myArr2, 0);

            Console.WriteLine("The new array contains:");
            for (i = 0; i < myArr2.Length; i++)
            {
                Console.WriteLine(" [{0}] {1}", i, myArr2[i]);
            }
            Console.WriteLine();

            // Clears the entire collection.
            list1.Clear();

            Console.WriteLine("After clearing the collection:");
            PrintForEach(list1);

        }

        // Uses the foreach statement which hides the complexity of the enumerator.
        // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
        public static void PrintForEach(StringCollection myCol)
        {
            Console.Write("PrintForEach: ");
            foreach (Object obj in myCol)
                Console.WriteLine(" {0}", obj);
            Console.WriteLine();
        }

        // Uses the enumerator. 
        // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
        public static void PrintEnumerating(StringCollection myCol)
        {
            Console.Write("PrintEnumerating: ");
            StringEnumerator myEnumerator = myCol.GetEnumerator();
            while (myEnumerator.MoveNext())
                Console.WriteLine(" {0}", myEnumerator.Current);
            Console.WriteLine();
        }

        // Uses the Count and Item properties.
        public static void PrintCountAndItem(StringCollection myCol)
        {
            Console.Write("PrintCountAndItem: ");
            for (int i = 0; i < myCol.Count; i++)
                Console.WriteLine(" {0}", myCol[i]);
            Console.WriteLine();
        }

    }
}

result:
Displays the elements using foreach:
PrintForEach:  RED
 orange
 yellow
 RED
 green
 blue
 RED
 indigo
 violet
 RED

Displays the elements using the IEnumerator:
PrintEnumerating:  RED
 orange
 yellow
 RED
 green
 blue
 RED
 indigo
 violet
 RED

Displays the elements using the Count and Item properties:
PrintCountAndItem:  RED
 orange
 yellow
 RED
 green
 blue
 RED
 indigo
 violet
 RED

After adding "* white" to the end and inserting "* gray" at index 3:
PrintForEach:  RED
 orange
 yellow
 * gray
 RED
 green
 blue
 RED
 indigo
 violet
 RED
 * white

After removing "yellow":
PrintForEach:  RED
 orange
 * gray
 RED
 green
 blue
 RED
 indigo
 violet
 RED
 * white

After removing all occurrences of "RED":
PrintForEach:  orange
 * gray
 green
 blue
 indigo
 violet
 * white

The new array contains:
 [0] orange
 [1] * gray
 [2] green
 [3] blue
 [4] indigo
 [5] violet
 [6] * white

After clearing the collection:
PrintForEach: