#include<iostream.h>

class Myclass
{
private:
    int A,B,C;
    static int sum;
public:
    Myclass(int a,int b,int c)
    {
        A=a;B=b;C=c;
        Myclass::sum=A+B+C;
    }
    void GetNumber();
    void GetSum();
};
void Myclass::GetNumber()
    {
        cout<<"A = "<<A<<"\tB = "<<B<<"\tC = "<<C<<endl;
    }
void Myclass::GetSum()
    {
    cout<<"sum = "<<Myclass::sum<<endl;
    }
int Myclass::sum=0;
void main()
{
    Myclass M(3,7,10),N(14,9,11);
    M.GetSum();
    N.GetSum();
}





为什么结果两个sum都是34

因为sum是静态的，他是属于类的，而不是某个对象所有

同意楼上

为什么不是20呢

如果要用sum分别显示20和34要怎么改呀

#include<iostream.h>

class Myclass
{
private:
    int A,B,C;
    int sum;
public:
    Myclass(int a,int b,int c)
    {
        sum=0;
        A=a;B=b;C=c;
        sum=A+B+C;
    }
    void GetNumber();
    void GetSum();
};
void Myclass::GetNumber()
    {
        cout<<"A = "<<A<<"\tB = "<<B<<"\tC = "<<C<<endl;
    }
void Myclass::GetSum()
    {
    cout<<"sum = "<<sum<<endl;
    }
void main()
{
    Myclass M(3,7,10),N(14,9,11);
    M.GetSum();
    N.GetSum();
}

不用静态成员就可以啦   很简单

cout<<"A = "<<A<<"\tB = "<<B<<"\tC = "<<C<<endl;
请问一下这个语句的作用是什么？

void Myclass::GetNumber()
    {
        cout<<"A = "<<A<<"\tB = "<<B<<"\tC = "<<C<<endl;
    }
输出当前对象的数据成员 a b c  的值啊

#include<iostream.h>

class Myclass
{
private:
    int A,B,C;
    static int sum;
public:
    Myclass(int a,int b,int c)
    {
        A=a;B=b;C=c;
        Myclass::sum=A+B+C;
    }
    void GetNumber();
    void GetSum();
};
void Myclass::GetNumber()
    {
        cout<<"A = "<<A<<"\tB = "<<B<<"\tC = "<<C<<endl;
    }
void Myclass::GetSum()
    {
    cout<<"sum = "<<Myclass::sum<<endl;
    }
int Myclass::sum=0;
void main()
{
    Myclass M(3,7,10);
    M.GetSum();
    Myclass N(14,9,11);
    N.GetSum();
}