迭代器模式（Iterator）

来源：互联网发布：win8如何设置网络连接编辑：程序博客网时间：2024/04/30 11:42

1.目的

当需要遍历（单种方式或多种方式）遍历一个组合对象时，使用遍历模式。该模式类似与将容器的接口进行封装，不对外直接暴露容器的接口的做法类似。

2.代码

#ifndef ITERATOR_H_#define ITERATOR_H_#include <list>#include <string>using namespace std;class PersonForIterator{public:PersonForIterator(){}string getName(){return name;}PersonForIterator(string arg){name = arg;}private:string name;};class Aggregate{public:virtual ~Aggregate(){}void insert(PersonForIterator& arg){lists.push_back(arg);}public:list<PersonForIterator> lists;};class Iterator{public:Iterator(Aggregate& agg):agg(agg){iter = agg.lists.begin();}PersonForIterator& first(){return *(agg.lists.begin());}PersonForIterator& next(){iter++;return *iter;}bool isDone(){return (iter == agg.lists.end());}private:Aggregate& agg;list<PersonForIterator>::iterator iter;};#endif /* ITERATOR_H_ */

#include "Iterator.h"#include <iostream>void iterator(){PersonForIterator p1("Tom");PersonForIterator p2("Allen");PersonForIterator p3("John");PersonForIterator p4("Jim");Aggregate agg;agg.insert(p1);agg.insert(p2);agg.insert(p3);agg.insert(p4);Iterator it(agg);PersonForIterator p = it.first();while(!it.isDone()){cout<<p.getName()<<endl;p = it.next();}}

输出：

Tom
Allen
John
Jim

0 0