2023 4 21

 注意double类型相运算的也要是double类型

如上例若把a变量更改为int类型则会导致结果出错

#include<iostream>
#include<string>
using namespace std;
class people{
protected:
    int age;
    string name;
public:
    people(){}
    people(int a,string str){
    age=a;
    name=str;
    }
    ~people(){}
    void setvalue(int m,string str){
    age=m;
    name=str;
    }
    virtual void display()=0;
};
class student:public people
{
private:
    int studentid;
public:
    student(){}
    student(int a,string str,int n):people(a,str){
    studentid=n;
    }
    ~student(){}
    void setid(int m){
    studentid=m;
    }
    void display(){
    cout<<"姓名:"<<name<<"\t"<<"年龄:"<<age<<"\t"<<"ID:"<<studentid<<endl;
    }
};
class teacher:public people
{
private:
    int teacherid;
public:
    teacher(){}
    teacher(int a,string str,int n):people(a,str){
    teacherid=n;
    }
    ~teacher(){}
    void setid(int m){
    teacherid=m;
    }
    void display(){
    cout<<"姓名:"<<name<<"\t"<<"年龄:"<<age<<"\t"<<"ID:"<<teacherid<<endl;
    }
};
int main(){
    int a1,a2;
    string str1,str2;
    int n,m;
student stu1;
teacher tea1;
people *p1;
p1=&stu1;
cout<<"请输入学生的姓名，年龄，学号"<<endl;
cin>>str1>>a1>>n;
cout<<"请输入教师的姓名，年龄，学号"<<endl;
cin>>str2>>a2>>m;
p1->setvalue(a1,str1);
stu1.setid(n);
p1->display();
p1=&tea1;
p1->setvalue(a2,str2);
tea1.setid(m);
p1->display();
return 0;
}