【设计模式】之八Iterator

来源：互联网发布：vscode webpack插件编辑：程序博客网时间：2024/04/27 17:35

Type: Behavioral

Iterator：提供一个方法连续访问一个聚合对象的元素，同时不暴露其底层表示

#include <iostream>using namespace std;#define Data intclass Iterator{public:    virtual Data* next()=0;};class ConcreteIterator: public Iterator{public:    ConcreteIterator(Data* data, int* size)    {        m_pData = data;        m_pSize = size;        mIndex = 0;    };    Data* next()    {        if(m_pData != NULL && mIndex < *m_pSize){            return &m_pData[mIndex++];        } else {            return NULL;        }    };   private:    int mIndex;    Data* m_pData;    int* m_pSize;};class Aggregate{public:virtual Iterator* createIterator() = 0;};class ConcreteAggregate: public Aggregate{public:    ConcreteAggregate(int size)    {        mSize = size;        mData = new Data[size];        for(int i=0;i<size; i++)            mData[i] = i;    };    Iterator* createIterator()    {        Iterator* iterator = new ConcreteIterator(this->mData, &this->mSize);        return iterator;    };private:    Data* mData;    int mSize;};int main(){Aggregate* pAggregate = new ConcreteAggregate(4);Iterator*  pIterator  = pAggregate->createIterator();    Data* data;    int count = 0;while (data = pIterator->next()){        if(count ++ > 10)            break;cout <<*data<<endl;}    system("pause");return 0;}