#include <iostream> using namespace std; class Product { public: Product(int m,int q,float p):num(m),quantity(q),price(p){}; void total(); static float average(); static void display(); private: int num; int quantity; float price; static float discount; static float sum;//销售总额 static int n;//销售件数 }; void Product::total()//计算销售总额,统计件数 { float rate=1.0; if(quantity>10) rate=0.98*rate; sum=sum+quantity*price*rate*(1-discount); n=n+quantity; } void Product::display() { cout<<"销售总额为 "<<sum<<",每件的平均售价为 "; cout<<average()<<endl; } float Product::average()//静态成员函数只能调用静态数据成员 { return(sum/n); } float Product::sum=0; int Product::n=0; float Product::discount=0.05; int main() { Product pro[3]={ Product(101,5,23.5),Product(102,12,24.56),Product(103,100,21.5) }; for(int i=0;i<3;i++) pro[i].total(); Product::display(); return 0; }