C++_练习—面积

面积

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代码示例：

#include <iostream>

using namespace std;

class circle {

public:
    void set_r(int rr);
    double c_circle();
    double s_circle();

private:
    int r;
};


void circle::set_r(int rr) {
    r = rr;
}

double circle::c_circle() {
    double  c = 0;
    c = r * 3.14 * 2 ;
    cout << "c = " << c << endl;
    return c;
}

double circle::s_circle() {
    double s = 0 ;
    s = r * r * 3.14;
    cout << "s = " << s << endl;
    return s;
}


int main(void) {
    class circle temp;
    temp.set_r(1);
    temp.c_circle();
    temp.s_circle();

    system("pause");

    return 0;
}