public
class
Element /div>
Iterator Pattern
This pattern provides a way to access elements from an aggregate sequentially. Microsoft's IEnumerable is one of the example of this pattern. Let me introduce this pattern using this interface.
{
public
string
Name { get;
set; }
}
public
class
Iterator: IEnumerable<element>
{
public
Element[] array;
public
Element this[int
i]
{
get
{
return
array[i];
}
}
#region IEnumerable<element> Members
public
IEnumerator<element> GetEnumerator()
{
foreach
(Element arr in
this.array)
yield
return
arr;
}
#endregion
#region IEnumerable Members
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
foreach
(Element arr in
this.array)
yield
return
arr;
{
}
#endregion
}
The iterator pattern in .NET can be implemented using IEnumerator and IEnumerable. An IEnumerator is an iterator object which has methods called MoveNext and Current. When the MoveNext is called for an IEnumerator the underlying sequence is moved one element
further and the Current property is set to the current object until it reaches the last element when the movenext fails with a false return value. The IEnumerable implemented for all collection or sequence in .NET creates an object of IEnumerator for that
particular sequence and gets the object to us.
The special keyword yield in C# automatically creates the IEnumerable and IEnumerator without need for the developer to implement these manually.