#include<iostream>
#include<string>
using namespace std;
class student
{
public:
    student(int a,string b,char c)
    {
        num=a;
        name=b;
        sex=c;
    }
    void display();
private:
    int num;
    string name;
    char sex;
};
void student::display()
{
    cout<<"num:"<<num<<"name:"<<name<<"sex:"<<sex<<endl;
}

class student1:public student
{
public:
    student1(int a,string b,char c,int a1,string b1,char c1,int d,string e):student(a, b, c),aaa(a1,b1,c1)
    {
        age=d;
        addr=e;
    }
    void display1()
    {
        display();
        cout<<"age:"<<age<<endl<<"addr:"<<addr<<endl;
    }
    void aaa_display()
    {
        aaa.display();

protected:
    student aaa;
    int age;
    string addr;
};


int main()
{
    student1 stud(1001,"wanglin",'f',1002,"lili",'d',19,"sadasdsa");
   
    stud.display1();
    stud.aaa_display();
    return 0;
}

又忘加括号

#include<iostream>
#include<string>
using namespace std;
class student
{
public:
    student(int a,string b,char c)
    {
        num=a;
        name=b;
        sex=c;
    }
    void display();
private:
    int num;
    string name;
    char sex;
};
void student::display()
{
    cout<<"num:"<<num<<"\t"<<"name:"<<name<<"\t"<<"sex:"<<sex<<endl;
}

class student1:public student
{
public:
    student1(int a,string b,char c,int a1,string b1,char c1,int d,string e):student(a, b, c),aaa(a1,b1,c1)
    {
        age=d;
        addr=e;
    }
    void display1()
    {
        display();
        cout<<"age:"<<age<<"\t"<<"addr:"<<addr<<"\t";//这里加了个跳转符，更清晰些；
    }
    void aaa_display()
    {
        aaa.display();}//楼主已经发现了，这里少了个“}”。
protected:
    student aaa;
    int age;
    string addr;
};


int main()
{
    student1 stud(1001,"wanglin",'f',1002,"lili",'d',19,"sadasdsa");
   
    stud.display1();
    stud.aaa_display();
    return 0;
}

小错误，多注意

加上括号后就对了。

   他有提示的啊。 你要看哈