1、货物出货与进货
#if 0
#include<iostream>
using namespace std;
/*
某商店经销一种货物。货物购进和卖出时以箱为单位。各箱
的重量不一样，因此商店需要记录目前库存的总重量，现在用
C++模拟商店货物购进和卖出的情况
*/
class Goods {
public:Goods() {weight = 0;next = NULL;cout << "创建了一个重量为：" << weight << "的货物" << endl;}Goods(int w) {//需要创建一个w的货物，并且仓库加这个重量weight = w;next = NULL;total_weight += w;cout << "创建了一个重量为：" << weight << "的货物" << endl;}static int get_total_wight() {return total_weight;}~Goods() {//需要删除一个w的货物，并且仓库减这个重量cout << "删除了一个重量为：" << weight << "的货物" << endl;total_weight -= weight;}
public:Goods *next;
private:int weight;static int total_weight;
};
int Goods::total_weight = 0;
void buy(Goods *&head, int w) {//创建一个货物 重量为wGoods *new_goods = new Goods(w);if (head == NULL)head = new_goods;else {new_goods->next = head; //头结点插入head = new_goods;}
}
void sale(Goods * &head) {if (head == NULL) {cout << "仓库为空" << endl;return;}Goods *temp = head;head = head->next;delete temp;cout << "saled." << endl;
}
int main(void) {int choice = 0;int w;Goods *head = NULL; //利用链表管理 无头指针do{cout << "1 进货" << endl;cout << "2 出货" << endl;cout << "0 退出" << endl;cin >> choice;switch (choice){case 1:cout << "请输入要创建货物的重量" << endl;cin >> w;buy(head, w);break;case 2:sale(head);break;case 0:return 0;break;default:break;}cout << "当前仓库的总重量是：" <<Goods::get_total_wight()<< endl;} while (1);
}
#endif
我的思路：
#if 0
#include<iostream>
using namespace std;
/*
某商店经销一种货物。货物购进和卖出时以箱为单位。各箱
的重量不一样，因此商店需要记录目前库存的总重量，现在用
C++模拟商店货物购进和卖出的情况
*/
class Goods {
public:Goods(int num, int weight) {m_num = num;m_weight = weight;}void get_in_good() {m_sum_weight += m_num*m_weight;}void get_out_good(int num, int weight) {m_sum_weight -= num*weight;}static int get_m_sum_weight(){return m_sum_weight;}
private:int m_num;int m_weight;static int m_sum_weight;
};
int Goods::m_sum_weight = 0;
int main() {Goods g1(1, 20);Goods g2(2, 30);Goods g3(3, 50);g1.get_in_good();g2.get_in_good();g3.get_in_good();g2.get_out_good(1, 30);cout << Goods::get_m_sum_weight() << endl;return 0;
}
#endif2、数组类的封装
MyArray.h
#pragma once
#include<iostream>
using namespace std;
class MyArray
{
public:friend ostream& operator<<(ostream& os, const MyArray &obj);friend istream& operator>>(istream& os, MyArray &obj);friend bool operator==(const MyArray &a1, const MyArray& a2); //全局函数bool operator!=(const MyArray& another); //成员函数MyArray();MyArray(int length);MyArray(const MyArray &obj);MyArray& operator=(const MyArray &obi);int& operator[](int index) const; void setData(int index, int value);int getData(int index);int getLength() const;~MyArray();
private:int m_length;int *m_space; //指向堆上空间 数组首地址
};MyArray.cpp
#include "MyArray.h"MyArray::MyArray() {cout << "MyArray()" << endl;m_length = 0;m_space = NULL;
}
MyArray::MyArray(int length){/*if (length < 0){m_length = 0;m_space = new int[length];}else {m_length = length;m_space = new int[length];}*///等价于if (length < 0){length = 0;}m_length = length;m_space = new int[length];
}
MyArray::MyArray(const MyArray &obj) {if (obj.m_length>=0){ if (m_space != NULL) {delete[] m_space;m_space = NULL;}this->m_length = obj.m_length;this->m_space = new int[this->m_length];for (int i = 0; i < m_length; i++) //数据元素深拷贝{this->m_space[i] = obj.m_space[i];}}
}
MyArray::~MyArray() {if (m_space != NULL) {delete[] m_space;m_space = NULL;}
}
MyArray& MyArray::operator=(const MyArray &another) {if (this == &another){return *this;}if (this->m_space != NULL) {delete this->m_space;this->m_space = NULL;this->m_length = 0;}if (another.m_length >= 0){this->m_length = another.m_length;this->m_space = new int[this->m_length];for (int i = 0; i < m_length; i++) //数据元素深拷贝{this->m_space[i] = another.m_space[i];}}return *this;
}
int& MyArray::operator[](int index) const{return this->m_space[index];
}void MyArray::setData(int index, int value) {if (m_space != NULL) {//a1.setData(i, i);m_space[index] = value;}}
int MyArray::getData(int index) {return m_space[index];
}
int MyArray::getLength() const {return m_length;
}
bool MyArray::operator!=(const MyArray& another) {/*if (this->getLength() != another.getLength()) {return true;}for (int i = 0; i < this->getLength(); i++) {if (this->m_space[i] != another.m_space[i])return true;}return false;*///等价于return !(*this == another);
}
ostream& operator<<(ostream& os, const MyArray &obj) { //防止被修改添加const后报错//原因分析：在调用getLengt()传入的是&obj,并不是const类型//安全性高的转换为安全性低的会报错//下面的operator[](&obj)传入的是&obj,并不是const类型 所以报错//修改方法就是加上在getLength() 函数后添加const//修改方法就是加上在operator[](int index)函数后添加constos << "遍历整个数组" << endl;//for (int i = 0; i <obj.m_length; i++) 无法修改for (int i = 0; i <obj.getLength(); i++){//os << obj.m_space[i] << " ";//等价于os << obj[i] << " ";}return os;
}
//istream& operator >> (istream& is,MyArray &obj) {
// cout << "请输入数组元素个数：";
// cin >> obj.m_length;
// obj.m_space = new int[obj.m_length];
// for (int i = 0; i < obj.m_length; i++)
// {
// int j;
// cin >> j;
// obj.m_space[i] = j;
// }
// return is;
//
//}
istream& operator>>(istream& is, MyArray &array) {cout << "请输入：" << array.getLength() << "个数" << endl;for (int i = 0; i < array.getLength(); i++){cin >> array[i];}return is;
}
bool operator==(const MyArray &a1, const MyArray& a2) {if (a1.getLength() != a2.getLength()) {return false;}for (int i = 0; i < a1.getLength(); i++){if (a1.m_space[i] != a2.m_space[i])return false;}return true;
}main.cpp
#include<iostream>
using namespace std;
#include"MyArray.h"int main() {MyArray a1(10);for (int i = 0; i < a1.getLength(); i++){//a1.setData(i, i);a1[i] = i + 10; //space[i]=i+10}cout << "print a1" << endl;for (int i = 0; i < a1.getLength(); i++){//cout<<a1.getData(i)<<" ";cout << a1[i] << " " ;}MyArray a2 = a1;cout << endl<<"print a2" << endl;for (int i = 0; i < a2.getLength(); i++){//cout<<a1.getData(i)<<" ";cout << a2[i] << " " ;}cout << endl;MyArray a3;a3 = a1;cout << endl << "print a3" << endl;for (int i = 0; i < a3.getLength(); i++){//cout << a3.getData(i) << " ";cout << a3[i] << " " ;}cout <<endl<< "<<操作符重载" << endl;cout << a3 << endl;MyArray array1(3);cin >> array1;cout << array1 << endl;if (array1 == a1) {cout << "相等" << endl;}elsecout << "不相等" << endl;if (array1 != a1) {cout << "不相等" << endl;}elsecout << "相等" << endl;
}
