program System_Collections_Specialized_StringCollection;

{$APPTYPE CONSOLE}
{$AUTOBOX ON}

uses
  System.Collections,
  System.Collections.Specialized;

type
  SamplesStringCollection = class
  public
    class procedure Main;
  private
    class procedure PrintValues(myCol: IEnumerable);
  end;

{ SamplesStringCollection }

class procedure SamplesStringCollection.Main;
type
  TArrayOfString = array of string;
var
  myArr2: TArrayOfString;
  myArr: TArrayOfString;
  i: Integer;
  myCol: StringCollection;
begin
  // Creates and initializes a new StringCollection
  myCol := StringCollection.Create;
  Console.WriteLine('Initial contents of 
                     the StringCollection:');
  PrintValues(myCol);

  // Adds a range of elements from an 
  //array to the end of the StringCollection
  myArr := TArrayOfString.Create
                 ('RED', 'orange', 'yellow',
                  'RED', 'green',  'blue',
                  'RED', 'indigo', 'violet', 'RED');
  myCol.AddRange(myArr);
  Console.WriteLine('After adding a range of elements:');
  PrintValues(myCol);

  // Adds one element to the end of the StringCollection 
  // and inserts another at index 3.
  myCol.Add('* white');
  myCol.Insert(3, '* gray');
  Console.WriteLine('After adding "* white" to the 
                     end and inserting "* gray" 
                     at index 3:');
  PrintValues(myCol);

  // Removes one element from the StringCollection
  myCol.Remove('yellow');
  Console.WriteLine('After removing "yellow":');
  PrintValues(myCol);

  // Removes all occurrences of a 
  // value from the StringCollection
  i := myCol.IndexOf('RED');
  while (i > -1) do
  begin
    myCol.RemoveAt(i);
    i := myCol.IndexOf('RED');
  end;

  // Verifies that all occurrences of "RED" are gone
  if myCol.Contains('RED') then
    Console.WriteLine('*** The collection 
                       still contains "RED".');
  Console.WriteLine('After removing all 
                     occurrences of "RED":');
  PrintValues(myCol);

  // Copies the collection to a new 
  // array starting at index 0
  SetLength(myArr2,myCol.Count);
  myCol.CopyTo(myArr2, 0);
  Console.WriteLine('The new array contains:');
  i := 0;
  while (i < System.Array(myArr2).Length) do
  begin
    Console.WriteLine('   [{0}] {1}', i, myArr2[i]);
    i := i + 1;
  end;
  Console.WriteLine;

  // Clears the entire collection
  myCol.Clear;

  Console.WriteLine('After clearing the collection:');
  PrintValues(myCol);
end;

class procedure SamplesStringCollection.PrintValues
                (myCol: IEnumerable);
var
  myEnumerator: System.Collections.IEnumerator;
begin
  myEnumerator := myCol.GetEnumerator;
  while myEnumerator.MoveNext do
  begin
    Console.WriteLine('   {0}', myEnumerator.Current);
  end;
  Console.WriteLine;
end;

//test program
begin
  SamplesStringCollection.Main;
end.