using
System;
using
System.Collections.Generic;
namespace
ConsoleApplication8
{
class
Program
{
static
void
Main(
string
[] args)
{
MusicTitles titles =
new
MusicTitles();
foreach
(
string
title
in
titles)
{
Console.WriteLine(title);
}
Console.WriteLine();
foreach
(
string
title
in
titles.Reverse())
{
Console.WriteLine(title);
}
Console.WriteLine();
foreach
(
string
title
in
titles.Subset(2, 2))
{
Console.WriteLine(title);
Console.ReadLine();
}
}
}
public
class
MusicTitles
{
string
[] names = {
"a"
,
"b"
,
"c"
,
"d"
};
public
IEnumerator<
string
> GetEnumerator()
{
for
(
int
i = 0; i < 4; i++)
{
yield
return
names[i];
}
}
public
IEnumerable<
string
> Reverse()
{
for
(
int
i = 3; i >= 0; i--)
{
yield
return
names[i];
}
}
public
IEnumerable<
string
> Subset(
int
index,
int
length)
{
for
(
int
i = index; i < index + length; i++)
{
yield
return
names[i];
}
}
}
}