Basically, iterator mode is not much to say, there are too many in the STL, generally used to traverse the data structure, its implementation is relatively simple.
The code is as follows:
Author:jeson yang//date:2014.12.10/ /file:main.cpp//////////////////////////////////////////////////////////////////////////#include <iostream >using namespace Std;class interator;class aggregate{public:virtual ~aggregate () {}virtual Interator* CreateItrator () =0{};virtual int getsize () =0{}virtual int GetItem (int index) =0{}protected:aggregate () {}};class concreteaggregate: Public aggregate{public:enum{size=3}; Concreteaggregate () {for (int i=0;i < size;i++) m_obj[i]=i;} ~concreteaggregate () {}interator* createitrator (); int GetItem (int index) {if (GetSize ()) return M_obj[index];else return-1;} int GetSize () {return size;} Private:int m_obj[size];}; Class Interator{public:virtual ~interator () {};virtual void first () =0;virtual void Next () =0;virtual bool IsDone () = 0; virtual int CurrentItem () =0;protected:interator () {}};class concreteinterator:public interator{public: Concreteinterator (aggregate* ag,int index=0) {M_ag=ag;m_indEx=index;} ~concreteinterator () {}void first () {m_index=0;} void Next () {if (M_index! = M_ag->getsize ())) m_index++;} BOOL IsDone () {return (m_index==m_ag->getsize ());} int CurrentItem () {return m_ag->getitem (m_index);} private:aggregate* M_ag;int M_index;};i nterator* Concreteaggregate::createitrator () {return new concreteinterator (this);} void Main () {aggregate* ag=new concreteaggregate (); interator* it=new Concreteinterator (AG); for (;! (It->isdone ()); It->next ()) {Cout<<it->currentitem () <<endl;} Delete It;delete AG;}
Iterator mode (c + + iterator mode)