Question

我有一个虚拟课程的人，从中派生到2个班级的学生和老师：

有些人可以告诉我如何将p [counter]初始化为老师或学生吗？

这是虚函数

class person 
{
public:
    string name;
    int age;
    virtual void print()=0;
};

第一个派生班主任

class teacher : public person
{
public:

    int salary;
    teacher();
    teacher(int x,string y,int z);
    void print();

};

第二个派生班学生

class student : public person
{
public:
    char grade;
    double fees;
    student();
    student(string a,int b,char c,double d);
    void print();

};




int main()
{
    cout<<"Insert 's' for student and 't' for teacher"<<endl;

    string S;
    cin>>S;
    person *p;

    here you either enter s for student or t for teacher, and also we create a dynamic array for p as type person


    for(int counter=0;counter<4;counter++)
    {
        if (S=="s" || S=="S")
        {

            string name;
            int age;
            char grade;
            int fees;
            cout<<"Input name,age,grade,fees"<<endl;
            cin>>name;
            cin>>age;
            cin>>grade;
            cin>>fees;
            p[counter]=student(name,age,grade,fees);
        }

上面是p [计数器无法初始化为学生的地方，它给了我一个错误，然后说p不是在运行时错误初始化我尝试添加新的，但它给了我一个编译错误... 否则如果（S ==“t”|| S ==“T”） {

            string name2;
            int age2;
            int salary;
            cout<<"Input age,name,salary"<<endl;
            cin>>name2;
            cin>>age2;
            cin>>salary;
            p[counter]=teacher(age2,name2,salary);
        }

这里我们对老师有同样的看法其他 { COUT＆LT;＆LT; “错误” ＆LT;

        cin>>S;

    }

    cout<<endl<<endl<<endl;


    delete [] p;
    return 0;
}

这里是函数实现

teacher::teacher()
{
    name="None";
    age=0;
    salary=0;
}
teacher::teacher(int x,string y,int z)
{
    name=y;
    age=x;
    salary=z;
}
void teacher::print()
{
    cout<<"Dr."<<name<<endl
        <<"age:"<<age<<endl
        <<"slary:"<<salary<<"$"<<endl;
}

student::student()
{
    name="None";
    age=0;
    grade='F';
    fees=0;
}
student::student(string a,int b,char c,double d)
{
    name=a;
    age=b;
    grade=c;
    fees=d;
}
void student::print()
{
    cout<<"Student: "<<name<<endl
        <<"Age: "<<age<<endl
        <<"Grade: "<<grade<<endl
        <<"Fees: "<<fees<<" $"<<endl;
}

Answer 1

有一些错误：

P是一个指针，你试图将它用作一个指针数组。

因为counter似乎循环了4次。因此，您可以将p定义为person *p[4]; 这将创建基类人员的指针数组。

然后在分配p[counter]=student(name,age,grade,fees);或p[counter]=teacher(age2,name2,salary);时，您必须使用new运算符。那就是

p[counter]=new student(name,age,grade,fees);

和

p[counter]=new teacher(age2,name2,salary);

从虚拟类数组初始化派生类

1 个答案: