股票系统类模型class体验

#ifndef STOCK00_H_
#define STOCK00_H_
#include<string>

class Stock
{
private:
	std::string company;
	long shares;
	double share_val;
	double total_val;
	void set_tot()	{total_val = share_val * shares;}
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();
};

#endif

 

#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
		shares = n;
	share_val = pr;
	set_tot();
}
void Stock::buy(long num, double price)
{
	if(num < 0)
		std::cout << "Number of shares purchased can`t be negative." << "Transcation is aborted.\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 purchased can`t be negative." << "Transcation is aborted.\n";	
	else if(num > shares)
		cout << "You cannot sell more than you have!" << "Transcation is aborted.\n";	
	else
	{
		shares -= num;
		share_val = price;
		set_tot();
	}
}
void Stock::update(double price)
{
	share_val = price;
	set_tot();
}
void Stock::show()
{
	std::cout << "Company: " << company
		<< " Shares: " << shares << '\n'
		<< " Share Price: $" << share_val
		<< " Total Worth: $" << total_val << '\n';
}

 

 

#include<iostream>
#include"stock00.h"
int main()
{
	Stock fluffy_the_cat;
	fluffy_the_cat.acquire("NanoSmart", 20, 12.50);
	fluffy_the_cat.show();
	fluffy_the_cat.buy(15, 18.125);
	fluffy_the_cat.show();
	fluffy_the_cat.sell(400, 20.00);
	fluffy_the_cat.show();
	fluffy_the_cat.buy(300000, 40.125);
	fluffy_the_cat.show();
	fluffy_the_cat.sell(300000, 0.125);
	fluffy_the_cat.show();
	return 0;
}

 

总体思路为：建立类模型→具体描述类模型→使用类模型

Ps：模型是可复用的。