// stock00.h
// Created by 吕百杨 on 2016/10/8.
//
#ifndef STOCK00_H_STOCK00_H
#define STOCK00_H_STOCK00_H
#include <string>
class Stock
{
private:
std::string company; //公司名称
long shares;//表示持有的股票数量
double share_val;//每股的价格
double total_val;//总价格
void set_tot() {total_val=shares*share_val;}//是内联函数，短小的函数就行;另一种形式在下面
//可以立即定义或者如其他函数一样用原型表示，对于描述函数的借口来说足够
//stock类对set_tot函数做的就是一种封装，将实现细节放在一起，并将它们与抽象分开
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();
//sell 和 update 都是 "方法"
//void Stock::update(double price),::表示了函数所属的类（说明可以将另一个类的成员名字也定义成update）
//此Stock类的其他函数不比使用::即可使用update（）方法
};//此处有冒号
/*
* inline void Stock::set_tot() //要使用inline在最前面，其他的与定义一个函数差不多，再注意Stock::std
* {
* total_val=shares*share_val;
* }
*
*
*
* */
/*
* Stock::Stock(const std::string &co,long n,double pr) 此为构造函数，注意stock：：stock，
* 与acquire函数相同，区别在于程序声明对象时，自动调用构造函数
{
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();
}
*/
#endif //STOCK00_H_STOCK00_H//stock00.cpp
#include <iostream>#include "stock00.h"//Stock kate,joe; 这创建了两个类对象，一个为kate，一个为joe 创建时每个对象都有自己的存储空间，用于储存其内部的变量和类成员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. " <<"Transaction 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 sold can't be negative. " <<"transaction is aborted.\n"; } else if(num>shares) { cout << "You can't sell more than you have! " << "transacton 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<<"companny "<<company <<"shares "<<shares<<'\n' <<"share price: "<<share_val <<"total price: "<<total_val<<'\n';}
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