cpp 10.7

10.7 stock20.h

#pragma once
#include

class Stock
{
private:
	std::string company;
	int shares;
	double share_val;
	double total_val;
	void set_tot() { total_val = shares * share_val; }
public:
	Stock();
	Stock(const std::string & co, long n = 0, double pr = 0.0);
	~Stock();
	void buy(long num, double price);
	void sell(long num, double price);
	void update(double price);
	void show()const;
	const Stock & topval(const Stock & s)const;
};

stock20.cpp

#include
#include"stock20.h"

Stock::Stock()
{
	
	company = "no name";
	shares = 0;
	share_val = 0.0;
	total_val = 0.0;
}

Stock::Stock(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
		shares = n;
	share_val = pr;
	set_tot();
}

Stock::~Stock()
{
	
}

void Stock::buy(long num, double price)
{
	if (num < 0)
	{
		std::cout << "Number of shares purchased can't be negative. "
			<< "Yransaction is abored.\n";

	}
	else
	{
		shares += num;
		share_val = price;
		set_tot();
	}
}

void Stock::sell(long num, double price)
{
	using std::cout;
	if (num < 0)
	{
		cout << "Number of shares sold can't be negative. "
			<< "Transaction is aborted.\n";

	}
	else if (num > shares)
	{
		cout << "You can't sell more than you have! "
			<< "Transaction is aborted.\n";
	}
	else
	{
		shares -= num;
		share_val = price;
		set_tot();
	}
}

void Stock::update(double price)
{
	share_val = price;
	set_tot();
}

void Stock::show() const
{
	using std::cout;
	using std::ios_base;

	ios_base::fmtflags orig =
		cout.setf(ios_base::fixed, ios_base::floatfield);
	std::streamsize prec = cout.precision(3);

	cout << "Company: " << company
		<< " Shares: " << shares << '\n';
	cout << " Share Price: $" << share_val;

	cout.precision(2);
	cout << " Total Worth: $" << total_val << '\n';

	cout.setf(orig, ios_base::floatfield);
	cout.precision(prec);
}

const Stock & Stock::topval(const Stock & s) const
{
	if (s.total_val > total_val)
		return s;
	else
		return *this;
}

usestock2.cpp

#include
#include "stock20.h"

const int STKS = 4;
int main()
{
	
		Stock stocks[STKS] = {
		Stock("NanoSmart", 12, 20.0),
		Stock("Boffo Objects", 200, 2.0),
		Stock("Monolithic Obelisks", 130, 3.25),
		Stock("Fleep Enterprises",60,6.5)
		};

		std::cout << "Stock holdings:\n";
		int st;
		for (st = 0; st < STKS; st++)
			stocks[st].show();

		const Stock * top = &stocks[0];
		for (st = 1; st < STKS; st++)
			top = &top->topval(stocks[st]);
		std::cout << "\nMost valuable holding:\n";
		top->show();

	system("pause");
	return 0;
}