习题6.3

几点收获：

枚举变量是整型的。（？）

记得给字符加单引号！

#include<iostream>   
using namespace std;

void showmenu();

void main()  
{ 
	showmenu();
	char choice;
	cin>>choice;
	while(choice!='c'&&choice!='p'&&choice!='t'&&choice!='g')
	{
		showmenu();
		cin>>choice;
	}
	switch(choice)
	{
	case 'c':cout<<"Why don't you go to a carnivore?"<<endl;
		break;
	case 'p':cout<<"So you like music,huh?"<<endl;
		break;
	case 't':cout<<"Maple is a tree."<<endl;
		break;
	case 'g':cout<<"Don't play games any more!Sit down and study."<<endl;
		break;
	default:cout<<"Sorry that's not a choice,Please choose again."<<endl;
	}
}  

void showmenu()
{
	cout<<"Please Enter your choice:\n"
		"c:Carnivore     p:Pianist\n"
		"t:Tree          g:Game\n";
}