数组迭代器中的hasNext（）方法

Question

那是我的通用数组头文件：

#ifndef ARRAY_H
#define ARRAY_H
#include "Number.h"
#include "Iterator.h"

//array is contius memory of numbers
class Array{
protected:
    //array has some contius cell of memory each include the data
    class Cell{
    public:
        Number* m_data;

        //c'tor:(inline)
        Cell(Number* num=NULL): m_data(num){};
        //D'tor (inline)
        ~Cell(){};
    };
    //composition class of iterator:
    class ArrayIterator:public Iterator{
    public:
        Cell* m_current;

        //C'tor:(inline)
        ArrayIterator(Cell* cell):m_current(cell){};
        //D'tor:
        ~ArrayIterator(){};

        //is there any next numbers
        bool hasNext()const;
        //is there any prev numbers
        bool hasPrev()const;

        //returning the current and getforward
        Number& next();
        //returning the current and getback
        Number& prev();

    };
    Cell* m_head,*m_last;
public:
    //C'tor:
    Array(const int amount);
    //D'tor:
    virtual ~Array(){delete[]m_head;};


    //Random access operator:
    Number& operator [] (const int i)const{return *m_head[i].m_data;};


};


#endif

将Number和Iterator视为抽象类，而Number表示通用数字。

我的问题：如何在ArrayIterator中实现hasNext（），因为ArrayIterator是一个合成类，并且它不“知道”数组的大小

Answer 1

为了实现hasNext()和hasPrev()方法， ArrayIterator需要知道要迭代的当前Array的边界在哪里。

这可以通过将Cell* m_head,*m_last与Cell* m_head,*m_last一起m_current在ArrayIterator ，或者通过存储指向Array对象的指针并安排ArrayIterator可以访问Array对象的m_head和m_last来完成。 无论哪种情况，您都需要在ArrayIterator存储其他信息。