第十五章编程练习(1)

来源：互联网发布：java判断日期是星期几编辑：程序博客网时间：2024/05/17 08:50

TV.h

#pragma once#ifndef TV_H_#define TV_H_//class Remote; #使用前向声明 让TV类知道Remote是一个类class Tv {private:int state;int volume;int maxchannel;int channel;int mode;int input;public:friend class Remote;//与Remote是友元enum{off,on};enum{MinVal,MaxVal=20};enum{Antenna,Cable};enum{TV,DVD};Tv(int s = off, int mc = 125) :state(s), volume(5),maxchannel(mc), channel(2), mode(Cable), input(TV) {};void onoff() { state = (state == on) ? off : on; }//电视是否打开bool ison()const { return state == on; }bool volup();//音量调节bool voldown();void chanup();//频道切换void chandown();void set_mode() { mode = (mode == Antenna) ? Cable : Antenna; }//有线还是无线void set_input() { input = (input == TV) ? DVD : TV; }//电视还是DVDbool remote_mode(Remote & r);//遥控器处于常规还是互动模式void settings(Remote & r)const;//显示所有设置};class Remote {private:friend class Tv;int mode;int remote_model;public:enum { Con, Take };Remote(int m = Tv::TV,int r = Con) :mode(m),remote_model(r) {}bool volup(Tv & t) {return t.volup();}bool voldown(Tv & t) { return t.voldown(); }void onoff(Tv & t) { t.onoff(); }void chanup(Tv& t) { t.chanup(); }void chandown(Tv & t) { t.chandown(); }void set_chan(Tv & t,int c) { t.channel = c; }void set_mode(Tv & t) { t.set_mode(); }void set_input(Tv & t) { t.set_input(); }void display()const;//显示常规还是互动模式};#endif

TV.cpp

#include "TV.h"#include <iostream>bool Tv::volup(){if (volume < MaxVal){volume++;return true;}return false;}bool Tv::voldown(){if (volume > MinVal){volume--;return true;}return false;}void Tv::chanup(){if (channel < maxchannel)channel++;elsechannel = 1;}void Tv::chandown(){if (channel > 1)channel--;elsechannel = maxchannel;}bool Tv::remote_mode(Remote & r){if (state == on){r.remote_model = (r.remote_model == Remote::Con) ? Remote::Take : Remote::Con;return true;}return false;}void Tv::settings(Remote & r) const{using std::cout;using std::endl;cout << "TV is " << (state == off ? "Off" : "On") << endl;if (state == on){cout << "Volume setting = " << volume << endl<< "Channel setting = " << channel << endl<< "Mode = "<< (mode == Antenna ? "antenna" : "cable") << endl<< "Input = "<< (input == TV ? "TV" : "DVD") << endl<< "Remote model = ";r.display();cout << endl;}}void Remote::display() const{std::cout << (remote_model == Con ? "Con" : "Take");}

main.cpp

#include <iostream>#include "TV.h"int main(){using std::cout;using std::cin;Tv s42;Remote grey;cout << "Initial settings for 42\" TV:\n";s42.settings(grey);s42.onoff();s42.chanup();cout << "\nAdjusted settings for 42 \" TV:\n";s42.chanup();s42.remote_mode(grey);cout << "\nAdjusted settings for 42 \" TV:\n";s42.settings(grey);grey.set_chan(s42, 10);grey.volup(s42);grey.volup(s42);cout << "\n42\" settings after using remote :\n";s42.settings(grey);Tv s58(Tv::on);s58.set_mode();s58.remote_mode(grey);grey.set_chan(s58, 28);cout << "\n58\" settings: \n";s58.settings(grey);cin.get();return 0;}

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