C++继承问题，还请各位解答

Question

#include <iostream>
#include <string.h>

using namespace std;

class Person
{
private:
    int m_age;
    char* m_name;

public:
    Person();

    Person(char* name, int age)
    {
        strcpy(this->m_name,name);
        this->m_age = age;
    }

    ~Person();

    void setname(char* name)
    {
        strcpy(this->m_name, name);
    }

    void setage(int age)
    {
        this->m_age = age;
    }

    void getname()
    {
        cout<<"my name is :"<<this->m_name<<endl;
    }

    void getage()
    {
        cout<<"my age is:"<<this->m_age<<endl;
    }
};

class Student:public Person
{
private:
    int m_class;
public:
    Student(char *name , int age , int room):Person(name,age)
    {
        this->m_class = room;
    };

    void setclass(int room)
    {
        this->m_class = room;
    }

    void getclass()
    {
        cout<<"my class is "<<this->m_class<<endl;
    }

    void disp()
    {
        this->getage();
        this->getclass();
        this->getname();
    }
};

int main()
{
    Person *p1 = new Person("som",18);
    p1->getage();
    p1->getname();
    Student *s1 = new Student("abab",20,1);
    s1->disp();

}

输出结果如下，只有p1的输出没有s1的输出

Answer 1

    char* m_name;

这是个空指针啊，没崩溃是运气好。

改动的方法很多，只要初始化这个变量就好。最简单的是为修改为定长字符串数组，如

    char m_name[255];

另外，main里new 两个类的时候，用了字面量字符串作为参数，这样最好在相关函数声明中明确为 const，如

   Person(const char* name, int age)
   void setname(const char* name)
   Student(const char *name , int age , int room):Person(name,age)