C++ Primer Plus, Chapter10对象和类，excercise

1.银行账户类，存款、取款

//account.h#include <string>#ifndef ACCOUNT_H_#define ACCOUNT_H_class Account{private:    std::string name;    std::string acctnum;    double balance;public:    Account (const std::string &client, const std::string &num, double bal = 0.0);//构造函数    void show() const;    void deposit(double cash);    void withdraw(double cash);};#endif//account.cpp#include "stdafx.h";#include "account.h"#include <iostream>Account::Account(const std::string &client, const std::string &num, double bal){    name = client;    acctnum = num;    balance = bal;}void Account::show() const{    std::cout << "name: " << name << ", acctnum: " << acctnum << ", balance: " << balance << "\n";}void Account::deposit(double cash){    if (cash < 0)        std::cout << "The cash you deposit can't be negative; Transaction is aborted.\n";    else        balance += cash;}void Account::withdraw(double cash){    if (cash < 0)        std::cout << "The cash you withdraw can't be negative; Transaction is aborted.\n";    else if (cash > balance)        std::cout << "You don't have more than $" << balance << "; Transaction is aborted.\n";    else        balance -= cash;}//main.cpp#include "stdafx.h"#include "account.h"#include <iostream>int main(){    Account wei = Account("wei lj", "123456", 1100.0);    wei.show();    std::cout << "After depositing $500:\n";    wei.deposit(500.0);    wei.show();    std::cout << "After withdrawing $2000:\n";    wei.withdraw(2000.0);    wei.show();    std::cout << "After withdrawing $1500:\n";    wei.withdraw (1500.0);    wei.show();    std::cin.get();    return 0;}

2.string对象和char数组存储姓名

//string对象和char数组的定义，作为参数，赋值的区别//person.h#include <string>#ifndef PERSON_H_#define PERSON_H_class Person{private:    static const int LIMIT = 25;    std::string lname;    char fname[LIMIT];public:    Person()    {        lname = "";        fname[0] = '\0';    }    Person(const std::string &ln, const char * fn = "Heyyou");    void show() const;    void FormalShow() const;};#endif//person.cpp#include "stdafx.h"#include "person.h"#include <iostream>Person::Person(const std::string &ln, const char *fn){    lname = ln;    strcpy(fname, fn);}void Person::show() const{    std::cout << fname << " " << lname << "\n";}void Person::FormalShow() const{    std::cout << lname << ", " << fname << "\n";}//main.cpp#include "stdafx.h"#include "person.h"#include <iostream>int main(){    Person one;    Person two("Smythecraft");    Person three = Person("Dimwiddy", "Sam");    one.show();    two.show();    two.FormalShow();    three.show();    three.FormalShow();    std::cin.get();    return 0;}

3.Golf类，用构造函数实现setgolf()方法的交互

//golf.h#ifndef GOLF_H_#define GOLF_H_class Golf{private:    static const int Len = 40;    char fullname[Len];    int handicap;public:    Golf(const char *name = "zhang san", int hc = 20);  //默认构造函数    int setgolf();    void reset_hc(int hc);    void showgolf() const;};#endif//golf.cpp#include "stdafx.h"#include "golf.h"#include <iostream>Golf ::Golf(const char *name, int hc){    strcpy(fullname, name);    handicap = hc;}int Golf::setgolf(){    char name[Len];    int hc;    std::cout << "Enter the fullname: ";    std::cin.getline(name, Len);    if (name[0] == '\0') //双等号！！        return 0;    else    {        std::cout << "Enter the handicap: ";        std::cin >> hc;        std::cin.get();        *this = Golf(name, hc); //*this = 是必需的        return 1;    }}void Golf::reset_hc(int hc){    handicap = hc;}void Golf::showgolf() const{    std::cout << fullname << ": " << handicap << std::endl;}//main.cpp#include "stdafx.h"#include <iostream>#include "golf.h"#include <ctime>int main(){    using namespace std;    Golf gf[5];    int i;    for (i = 0; i < 5; i++)    {        int n = gf[i].setgolf();        if (n == 0) //双等号！！            break;        else            //setgolf(gf[i]);            continue;    }    cout << i << endl;    cout << "Reset handicap to new value:\n";    for (int j = 0; j < i; j++)    {        int hc;        cout << "Enter the new handicap: ";        cin >> hc;        gf[j].reset_hc(hc);    }    cout << "Display contents of golf structure:\n";    for (int j = 0; j < i; j++)        gf[j].showgolf();//j写成了i,要认真！    clock_t delay = 10 * CLOCKS_PER_SEC;    clock_t start = clock();    while (clock() - start < delay)        ;    return 0;}

4.Sales类，用构造函数实现setsales()方法的交互、名称空间

//namespace.h#ifndef NAMESPACE_H_#define NAMESPACE_H_namespace SALES{    class Sales    {    private:        static const int QUARTERS = 4;        double sales[QUARTERS];        double average;        double max;        double min;    public:        Sales(const double *ar, int n); //因为不会写数组的默认参数值，所以不是默认构造函数        void setsales();        void showsales() const;    };}#endif//namespace.cpp#include "stdafx.h"#include "namespace.h"#include <iostream>namespace SALES{    Sales::Sales(const double *ar, int n)    {        int i;        for (i = 0; i < n; i++)            sales[i] = ar[i];        for (int j = i; j < n; j ++)            sales[j] = 0;        double sum = 0;        for (int j = 0; j < QUARTERS; j++)            sum += sales[j];        average = sum / QUARTERS;        double max1 = sales[0];        for (int j = 1; j < QUARTERS; j++)        {            if (sales[j] > max1)                max1 = sales[j];        }        max = max1;        double min1 = sales[0];        for (int j = 1; j < QUARTERS; j++)        {            if (sales[j] < min1)                min1 = sales[j];        }        min = min1;    }    void Sales::setsales()    {        double ar[QUARTERS];        int i = 0;        std::cout << "Enter a sale: ";        while (std::cin >> ar[i])        {            i++;            if (i < QUARTERS)                std::cout << "Enter a sale (q to quit): ";            else                break;        }        *this = Sales(ar, i); //!!!!!! *this = 必须要，没有的话设置的值不能传递给调用该方法的对象    }    void Sales::showsales() const    {        for (int i = 0; i < QUARTERS; i++)        {            std::cout << "sales: " << sales[i] << "\t";        }        std::cout << std::endl;        std::cout << "average: " << average << std::endl;        std::cout << "max: " << max << std::endl;        std::cout << "min: " << min << std::endl;    }}//mian.cpp#include "stdafx.h"#include <iostream>#include "namespace.h"#include <ctime>using namespace SALES;int main(){    using namespace std;    double ar[4] = {1.1, 1.2, 1.3, 1.4};    Sales s1 = Sales(ar, 4); //先用构造函数显式初始化，不能不显式初始化，非交互式    Sales s2 = Sales(ar, 4);    s2.setsales();    cout << "Display s1:\n";    s1.showsales(); //重新设置s2的值，交互式    cout << "Display s2:\n";    s2.showsales();    clock_t delay = 10 * CLOCKS_PER_SEC;    clock_t start = clock();    while (clock() - start < delay)        ;    return 0;}

5.从栈中添加和删除customer结构

//stack.h#ifndef STACK_H_#define STACK_H_struct customer{    char fullname[35];    double payment;};typedef customer Item;class Stack{private:    enum {MAX = 10};    Item items[MAX];    int top;public:    Stack();    bool isempty() const;    bool isfull() const;    bool push(const Item &item);    bool pop(Item &item);};#endif//stack.cpp#include "stdafx.h"#include "stack.h"Stack::Stack(){    top = 0;}bool Stack::isempty() const{    return top == 0;}bool Stack::isfull() const{    return top == MAX;}bool Stack::push(const Item &item){    if (top < MAX)    {        items[top++] = item;  //一开始top还是原来的数，执行完本句之后才+1        return true;    }    else        return false;}bool Stack::pop(Item &item){    if (top > 0)    {        item = items[--top]; //top为个数，比数组最大索引大1，因此先要-1        return true;    }    else        return false;}//main.cppint main(){    using namespace std;    Stack st;    char ch;    Item po;    cout << "Please enter A to add a purchase order,\n"         << "p to process a PO, or Q to quit.\n";    double total = 0;    while (cin >> ch && toupper(ch) != 'Q')    {        while (cin.get() != '\n')            continue;        if (!isalpha(ch))        {            cout << '\a';            continue;        }        switch(ch)        {        case 'A':        case 'a':            cout << "Enter the fullname of the customer: ";            cin.getline(po.fullname, 35);            cout << "Enter the payment: ";            cin >> po.payment;            if (st.isfull())                cout << "stack already full\n";            else                 st.push(po);            break;        case 'P':        case 'p':            if (st.isempty())                cout << "stack already empty\n";            else            {                st.pop(po);                total += po.payment;                cout << "PO #" << po.fullname << ": " << po.payment << " popped, total $" << total << " popped\n";            }            break;        }        cout << "Please enter A to add a purchase order,\n"             << "p to process a PO, or Q to quit.\n";    }    cout << "Bye!\n";    cin.get();    return 0;}

6.Move类

//move.h#ifndef MOVE_H_#define MOVE_H_class Move{private:    double x;    double y;public:    Move(double a = 0, double b = 0);    void showmove() const;    Move add(const Move &m) const;    void reset(double a = 0, double b = 0);};#endif//move.cpp#include "stdafx.h"#include "move.h"#include <iostream>Move::Move(double a, double b){    x = a;    y = b;}void Move::showmove() const{    std::cout << "x = " << x << ", y = " << y << "\n";}Move Move::add(const Move & m) const{    Move mm;    mm.x = this->x + m.x; //this ！！！    mm.y = this->y + m.y;    return mm;}void Move::reset(double a, double b){    x = a;    y = b;}//main.cpp#include "stdafx.h"#include "move.h"#include <iostream>int main(){    Move m1 = Move(2.0, 2.0);    Move m2 = Move(1.0, 1.0);    Move m3;    std::cout << "#m1\n";    m1.showmove();    std::cout << "#m2\n";    m2.showmove();    std::cout << "#m3\n";    m3.showmove();    std::cout << "After add(), m3 = m1 + m2,show m3\n";    m3 = m1.add(m2);    m3.showmove();    std::cout << "After reset(),show m3\n";    m3.reset(5.0,5.0);    m3.showmove();    std::cin.get();    return 0;}

7.Plorg类

//plorg.h#ifndef PLORG_H_#define PLORG_H_class Plorg{private:    char name[20];    int CI;public:    Plorg(const char *n = "Plorga", const int ci = 50);    void reset_ci(int ci);    void show() const;};#endif//plorg.cpp#include "stdafx.h"#include "plorg.h"#include <iostream>Plorg::Plorg(const char *n, int ci){    strcpy(name, n);    CI = ci;}void Plorg::reset_ci(int ci){    CI = ci;}void Plorg::show() const{    std::cout << name << ": " << CI << "\n";}//main.cpp#include "stdafx.h"#include "plorg.h"#include <iostream>int main(){    Plorg pl1;    Plorg pl2 = Plorg("zhangsan", 55);    std::cout << "show pl1, pl2\n";    pl1.show();    pl2.show();    std::cout << "reset the CI in pl1\n";    pl1.reset_ci(20);    pl1.show();    std::cin.get();    return 0;}

8.列表（用类实现）、指针函数

//重点：：指针函数的写法//list.h#ifndef LIST_H_#define LIST_H_typedef int Item;const int MAX = 10;class List{private:    int top;    Item items[MAX];public:    List();    bool add(const Item & item);    bool isempty() const;    bool isfull() const;    void visit(void (*pf)(Item & item)); //直接这么写};#endiflist.cpp#include "stdafx.h"#include "list.h"List::List(){    top = 0;}bool List::add(const Item & item){    if (top < MAX)    {        items[top++] = item; //top为个数        return true;    }    else        return false;}bool List::isempty() const{    return top == 0;}bool List::isfull() const{    return top == MAX;}void List::visit(void (*pf)(Item & item)){    for (int i = 0; i < top; i++)        (*pf)(items[i]); //调用指针函数}//main.cpp#include "stdafx.h"#include "list.h"#include <iostream>#include <ctime>void print(Item & item); //指针函数原型int main(){    using namespace std;    List l;    int n;    cout << "Enter an item: ";    while (cin >> n)    {        if (l.isfull())        {            cout << "the list already full.\n";            break;        }           else        {            l.add(n);            cout << "Enter an item (q to quit): ";        }       }    void (*pf)(Item &item); //声明函数指针    pf = print; //赋地址    l.visit((*pf)); //调用成员函数visit()    clock_t delay = 10 * CLOCKS_PER_SEC;    clock_t start = clock();    while (clock() - start < delay)        ;    cin.get();    cin.get();    return 0;}void print(Item & item) //指针函数的原函数的定义{    std::cout << item << "\n"; }