网站开发设计图psd,驻马店广告制作公司,四川高速建设公司网站,先做网站还是先域名备案《C游戏编程入门》第8章 类#xff1a;Critter Caretaker 8.1 定义新类型08.simple_critter.cpp 8.2 使用构造函数08.constructor_critter.cpp 8.3 设置成员访问级别08.private_critter.cpp 8.4 使用静态数据成员与静态成员函数08.static_critter.cpp 8.5 Critter Caretaker游… 《C游戏编程入门》第8章 类Critter Caretaker 8.1 定义新类型08.simple_critter.cpp 8.2 使用构造函数08.constructor_critter.cpp 8.3 设置成员访问级别08.private_critter.cpp 8.4 使用静态数据成员与静态成员函数08.static_critter.cpp 8.5 Critter Caretaker游戏08.critter_caretaker.cpp 8.1 定义新类型
08.simple_critter.cpp
#include iostream
using namespace std;class Critter // 类定义定义新类型Critter
{
public:int m_Hunger; // 声明数据成员void Greet(); // 声明成员函数
};void Critter::Greet() // 成员函数定义
{cout Hi. Im a critter. My hunger level is m_Hunger .\n;
}int main()
{Critter crit1; // 对象实例化Critter crit2;crit1.m_Hunger 9; // 对象操作cout crit1s hunger level is crit1.m_Hunger .\n;crit2.m_Hunger 3;cout crit2s hunger level is crit2.m_Hunger .\n\n;crit1.Greet(); // 成员函数调用crit2.Greet();return 0;
}8.2 使用构造函数
构造函数实例化新对象时自动调用通常初始化工作给数据成员赋值。
08.constructor_critter.cpp
#include iostream
using namespace std;class Critter
{
public:int m_Hunger;Critter(int hunger 0); // 声明构造函数提供默认参数void Greet();
};Critter::Critter(int hunger) // 定义构造函数
{cout A new critter has been born! endl;m_Hunger hunger;
}void Critter::Greet()
{cout Hi. Im a critter. My hunger level is m_Hunger .\n\n;
}int main()
{Critter crit(7);crit.Greet();return 0;
}8.3 设置成员访问级别
避免直接修改或访问对象的数据成员让成员函数维护。
08.private_critter.cpp
#include iostream
using namespace std;class Critter
{
public: // begin public sectionCritter(int hunger 0);int GetHunger() const;void SetHunger(int hunger);private: // begin private sectionint m_Hunger;
};Critter::Critter(int hunger): m_Hunger(hunger)
{cout A new critter has been born! endl;
}int Critter::GetHunger() const // const不能修改非静态数据成员值不能调用非常量成员函数
{return m_Hunger;
}void Critter::SetHunger(int hunger)
{if (hunger 0){cout You cant set a critters hunger to a negative number.\n\n;}else{m_Hunger hunger;}
}int main()
{Critter crit(5);// cout crit.m_Hunger; -- illegal, m_Hunger is private!cout Calling GetHunger(): crit.GetHunger() \n\n;cout Calling SetHunger() with -1.\n;crit.SetHunger(-1);cout Calling SetHunger() with 9.\n;crit.SetHunger(9);cout Calling GetHunger(): crit.GetHunger() \n\n;return 0;
}8.4 使用静态数据成员与静态成员函数
08.static_critter.cpp
#include iostream
using namespace std;class Critter
{
public:static int s_Total; // 静态成员变量声明// total number of Critter objects in existenceCritter(int hunger 0);static int GetTotal(); // 静态成员函数声明private:int m_Hunger;
};int Critter::s_Total 0; // 静态成员变量定义并初始化Critter::Critter(int hunger) : m_Hunger(hunger)
{cout A critter has been born! endl;s_Total;
}int Critter::GetTotal() // 静态成员函数定义不能访问非静态数据成员
{return s_Total;
}int main()
{cout The total number of critters is: ;cout Critter::s_Total \n\n; // 访问静态常用变量Critter crit1, crit2, crit3;cout \nThe total number of critters is: ;cout Critter::GetTotal() \n; // 调用静态成员函数return 0;
}8.5 Critter Caretaker游戏
08.critter_caretaker.cpp
#include iostream
using namespace std;class Critter
{
public:Critter(int hunger 0, int boredom 0);void Talk();void Eat(int food 4);void Play(int fun 4);private:int m_Hunger; // 饥饿程度int m_Boredom; // 厌倦程度int GetMood() const;void PassTime(int time 1);
};Critter::Critter(int hunger, int boredom): m_Hunger(hunger), m_Boredom(boredom)
{
}inline int Critter::GetMood() const
{return (m_Hunger m_Boredom);
}void Critter::PassTime(int time)
{m_Hunger time;m_Boredom time;
}void Critter::Talk()
{cout Im a critter and I feel ;int mood GetMood();if (mood 15)cout mad.\n;else if (mood 10)cout frustrated.\n;else if (mood 5)cout okay.\n;elsecout happy.\n;PassTime();
}void Critter::Eat(int food)
{cout Brruppp.\n;m_Hunger - food;if (m_Hunger 0)m_Hunger 0;PassTime();
}void Critter::Play(int fun)
{cout Wheee!\n;m_Boredom - fun;if (m_Boredom 0)m_Boredom 0;PassTime();
}int main()
{Critter crit;crit.Talk();int choice;do{cout \nCritter Caretaker\n\n;cout 0 - Quit\n;cout 1 - Listen to your critter\n;cout 2 - Feed your critter\n;cout 3 - Play with your critter\n\n;cout Choice: ;cin choice;switch (choice){case 0:cout Good-bye.\n;break;case 1:crit.Talk();break;case 2:crit.Eat();break;case 3:crit.Play();break;default:cout \nSorry, but choice isnt a valid choice.\n;}} while (choice ! 0);return 0;
}
