4. 自动售票机例子

C++书写规范

每一个类需要有.h和.cpp文件.

//TicketMachine.h (声明)/* * TicketMachine.h * Created on: 2017/12/11 * Author: WangZhen*/#ifndef TICKETMACHINE_H_#define TICKETMACHINE_H_class TicketMachine{  public:    TicketMachine();    virtual ~TicketMachine();    void showPrompt();    void insertMoney(int money);    void showBalance();    void printTicket();    void showTotal();  private:    const int price;    int balance;    int total;};//TicketMachine.cpp (定义)/* * TicketMachine.cpp * Created on: 2017/12/11 * Author: WangZhen*/#include "TicketMachine.h"#include  <iostream>using namespace std;TicketMachine::TicketMachine() //构造函数{}TicketMachine::~TicketMachine() //析构函数{}void TicketMachine::showPrompt(){   cout << "something";}void TicketMachine::insertMoney(int money){   balance += money;}void TicketMachine::showBalance(){   cout << balance;}#endif/* * main.cpp * Created on: 2017/12/11 * Author: WangZhen * /#include "TicketMachine.h"int main(){   TicketMachine tm;   tm.insertMoney(100);   tm.showBalance();   return 0;}

错误一:
此代码程序将运行失败, 原始是: const int price，由于price是const,所以需要初始化.
所以构造函数修改为:
TicketMachine::TicketMachine():PRICE(0)
{
}

错误二:
未给int balance,int total赋初始值. 在构造函数里初始化类的私有成员变量.
TicketMachine::TicketMachine:PRICE(0),balance(0),total(0)
{
}

::称呼为域的解析符.