2.cpp

用c++类的方式在DOS界面下输入字符的程序

// Listing 20_1
// More practice with OOPs
// Introducing the DESTRUCTOR

#include <iostream.h>
#include <string.h>

class StringThings {
				private:
					char str[21];
					char FirstLetter;

				public :
					void First(void);
					void Show(void);
					StringThings(char s[21]);
					~StringThings(void);
			};

void StringThings::First(void)
{
	if (strlen(str) < 1)
		FirstLetter = '?';
	else
		FirstLetter = str[0];
}

void StringThings::Show(void)
{
	cout << FirstLetter << endl;
}

StringThings::StringThings(char s[21])
{
	strcpy(str,s);
}

StringThings::~StringThings(void)
{
	cout << endl << "Hello!" << endl << endl;
}

main()
{
	StringThings Test("PAUL");
	Test.First();
	Test.Show();
	return(0);
}