一、程序清单

stock00.h 

// stock00.h -- Stock class interface
// version 00
#ifndef STOCK00_H_
#define STOCK00_H_

#include <string>  

class Stock  // class declaration
{
private:
	std::string company;
	long shares;
	double share_val;
	double total_val;
	void set_tot() { total_val = shares * share_val; }
public:
	void acquire(const std::string & co, long n, double pr);
	void buy(long num, double price);
	void sell(long num, double price);
	void update(double price);
	void show();
};    // note semicolon at the end

#endif

stock00.cpp 

// stock00.cpp -- implementing the Stock class
// version 00
#include <iostream>
#include "stock00.h"

void Stock::acquire(const std::string & co, long n, double pr)
{
	company = co;
	if (n < 0)
	{
		std::cout << "Number of shares can't be negative; "
			<< company << " shares set to 0.\n";
		shares = 0;
	}
	else