C++重载下标操作符[](二)

#include 
using namespace std;

class Array{
public:
    Array(int length=0);//构造函数
    ~Array();           //析构函数

public:
    int &operator[](int i);             //重载操作符[]
    const int &operator[](int i)const ;

public:
    int length() const {return m_length;}  //获取数组长度
    void display() const;

private:
    int m_length; //数组长度
    int *m_p;     //数组指针
};


//新初始化一个数组
Array::Array(int length):m_length(length) {
    if (length==0){
        m_p=NULL;
    }
    else
    {
        m_p=new int [length];
    }
}

Array::~Array(){
    delete [] m_p;
}

int &Array::operator[](int i){
    return m_p[i];
}

const int & Array::operator[](int i) const {
    return m_p[i];
}

void Array::display() const {

    for (int i=0;i