The Iterator Design Pattern

Iterator Solutions

nCode unification

“This is Smalltalk.”

array do: [ :value | sum := sum + value ].

array do: [ :value | product := product * value ].

array do: [ :value | Transcript nextPutAll: value printString ].

array do: [ :value | stream nextPutAll: value printString ].

// This is C#

foreach (int value in array)

max=max<value ? value : max;

foreach (int value in array)

min=value<min ? value : min;


	Internal iterators can be used to remove the duplicated traversal code. We’ll distinguish internal and external iterators shortly.