Invoice 类，C++学习经典例子

#include<iostream> #include<string> using namespace std; class Invoice { public: Invoice(string, string, int, int); void setID(string); string getID(); void setDescription(string); string getDescription(); void setNumber(int); int getNumber(); void setPrice(int); int getPrice(); int getInvoiceAmount(); private: string ID; string desc; int number; int price; }; Invoice::Invoice(string id, string des, int num, int pri) { setID(id); setDescription(desc); setNumber(num); setPrice(pri); } void Invoice::setID(string id) { ID = id; } string Invoice::getID() { return ID; } void Invoice::setDescription (string des) { desc = des; } string Invoice::getDescription () { return desc; } void Invoice::setNumber(int num) { if(num >= 0) number = num; if(num < 0) number = 0; cout<<"The number can not be set to 0!"<<endl; } int Invoice::getNumber() { return number; } void Invoice::setPrice(int pri) { if(pri >= 0) price = pri; if(pri < 0) number = 0; cout<<"Tne price can not be set to 0!"<<endl; } int Invoice::getPrice() { return price; } int Invoice::getInvoiceAmount() { return number * price; } int main() { Invoice invoice("20115328", "goog enough to buy", 3, 10); cout<<"ID:"<<invoice.getID()<<endl; cout<<"desc:"<<invoice.getDescription()<<endl; cout<<"number:"<<invoice.getNumber()<<endl; cout<<"price:"<<invoice.getPrice()<<endl; cout<<"invoice amount:"<<invoice.getInvoiceAmount()<<endl; invoice.setID("123456"); invoice.setDescription("Good"); invoice.setNumber(-5); invoice.setPrice(20); cout<<"\nThe information of pruducrt is:"<<endl; cout<<"ID:"<<invoice.getID()<<endl; cout<<"decs:"<<invoice.getDescription()<<endl; cout<<"number:"<<invoice.getNumber()<<endl; cout<<"price:"<<invoice.getPrice()<<endl; cout<<"invoice amount:"<<invoice.getInvoiceAmount()<<endl; }