demo_6_const_object_3.cpp

对于一个初涉VC＋＋的人来书

//************************************************

# include <iostream.h>

class Student
{
public:
	Student(int n,float s):num(n),score(s){}
	void change(int n,float s) const {num=n;score=s;}
    void display() const {cout<<num<<" : "<<score<<endl;}
private:
	mutable int num;
    mutable float score;
};

int main()
{
	const Student stud(101,78.5);

	//只能用常成员函数访问常对象的数据成员
	//若数据成员声明为mutable,则允许常成员函数修改常对象数据成员的值
	stud.display();
	stud.change(101,88.5);
	stud.display();

	return 0;
}