// Example program
#include <iostream>
#include <string>
using namespace std;
class circle {
private:
double r;
double const pi=3.14;
public:
circle(double rad){
r=rad;
}
void periArea(){
double p,s;
p=2*pi*r;
s=pi*pi*r;
cout<<"\nS= "<<s<<endl;
cout<<"\nP= "<<p<<endl;
}
friend void changeRad(circle circle, double newrad);
};
void changeRad(circle circle, double newrad){
circle.r=newrad;
}
int main()
{
double inpr,newr;
cout<<"input radius: ";
cin>>inpr;
circle c1(inpr);
c1.periArea();
cout<<"\ninput new radius: ";
cin>>newr;
changeRad(c1,newr);
c1.periArea();
}
我有这个CPP代码,必须定义一个类圈计算周长和面积,然后使用朋友函数改变半径并再次计算面积和周长。但是,即使在更改函数后,我也会得到相同的p和s值。值不变
那很好。你打算***问一个问题***? – abelenky