C++在类中对变量声明的时候就已经创建了该变量了么？或者说已经为该变量分配内存了，只是内存中的数是未知的。
代码如下：
//student.h
 class student
{public:
     int score;
     int   num;
 public:
     student();
     student(int s,int n);
     void f1();
     void f2();
};

//student.cpp  
student::student(){}
student::student(int s,int m)
{   
    score=s;
    num=m;
}

void student::f1()
{   
    score=score+1;
    num=num+1;
    cout<<"score="<<score<<",  "<<"num="<<num<<endl;
}

void student::f2()
{
    score=score+2;
    num=num+2;
    cout<<"score="<<score<<",  "<<"num="<<num<<endl;
}

//main
#include "student.h"
void main()
{
    student op;
    op.f1();
    op.f2();
}

输出为：-58993459，-58993459
        -58993457，-58993457