迭代器的本质：对象。

迭代器与指针类似，通过迭代器可以指向容器中的某个元素，还可以对元素进行操作。

迭代器统一规范了遍历方式。不同的数据结构可以用统一的方式去遍历。

接下来是一个自定义迭代器的代码示例。

#include<iostream>
using namespace std;struct List
{int n;List* pnext;
};void AddNode(List*& rpHead, List*& rpEnd, int n)
{List* ptemp = new List;ptemp->n = n;ptemp->pnext = NULL;if (NULL == rpHead){rpHead = ptemp;}else{rpEnd->pnext = ptemp;}rpEnd = ptemp;
}class Iterator//自定义的一个迭代器
{
private:List* p;
public:Iterator(List* p){this->p = p;}
public:bool operator != (List* p){if (this->p != p){return true;}else{return false;}}int operator*(){return p->n;}List* operator++(int){List* pTemp = p;p = p->pnext;return pTemp;}
};
int main()
{List* pHead = NULL;List* pEnd = NULL;AddNode(pHead, pEnd, 1);AddNode(pHead, pEnd, 2);AddNode(pHead, pEnd, 3);AddNode(pHead, pEnd, 4);/*while (pHead != NULL)//原本的链表遍历方式{cout << pHead->n << endl;pHead = pHead->pnext;}*/Iterator ite = pHead;while (ite != NULL){cout << *ite << endl;ite++;}return 0;
}