定义了一个类：
class SimpleCat
{
public:
    SimpleCat();
    ~SimpleCat();
    void SetAge(int age){*itsAge=age;}
    int GetAge(){return *itsAge;}

    void SetWeight(int weight){*itsWeight=weight;}
    int GetWeight(){return *itsWeight;}

private:
    int *itsAge=0;
    int *itsWeight;
};

SimpleCat::SimpleCat()
{
    itsAge=new int(2);
    itsWeight=new int(20);
}

SimpleCat::~SimpleCat()
{
    delete itsAge;
    delete itsWeight;
}

红色区域的私有数据用指针表示，但是为什么我给指针赋初值，编译器就报错啊？书上不说最好每次声明指针的时候都赋初值吗？
错误：error C2252: 'itsAge' : pure specifier can only be specified for functions

哦对对，谢谢了啊！

还行，反正有点绕，好好看还是挺好学的。