C++ 获取以下c+;的链接器错误+;代码

C++ 获取以下c+;的链接器错误+;代码,c++,c++builder,object-oriented-analysis,C++,C++builder,Object Oriented Analysis,我最近开始学习面向对象编程。对于以下代码,我得到了链接器错误 #include <iostream> #include <string> #include <cstdlib> using namespace std; class person{ public: string name; person(); person(string n){ name = n ;

我最近开始学习面向对象编程。对于以下代码,我得到了链接器错误

#include <iostream>
#include <string>
#include <cstdlib>
using namespace std;

class person{
    public:
        string name;
        person();
        person(string n){
            name = n ;
        }

        void setName(string k){
            name = k;
        }
        string getName(){
            return name;
        }
};
class student : public  person {
    public:
        string major;
        void setMajor(string m){
            major = m;
        }
        string getMajor(){
            return major;
        }
};
class faculty : public person{
    public:
        string department;
        faculty(string dept){
            department = dept;
        }
        void setDepartment(string depart){
            department = depart;
        }
        string getDepartment(){
            return department;
        }
};

int main() {

    student s;

    s.setName("james");
    s.setMajor("computer science");

    string p = s.getName();
    string p2 = s.getMajor();

    cout << "student name and mjor is :" << p << p2 << endl;
    faculty f("nanotech");
    f.setName("chris");
    f.setDepartment("electrical");
    string f1 = f.getName();
    string f2 = f.getDepartment();
    cout << "facult name and department :" << f1 << f2 << endl;

    return 0;
}

在类person中,有一个已声明但未定义的构造函数。编译器允许您编译类,但链接器会查找实现(称为):

问题是,您继承了学生和教师中的人,您使用默认构造函数,但从未实现它。尝试添加实现,链接器错误将消失:

class person{
       public:
          string name;
          person(){}        //constructor implemented
          person(string n){
              name = n ;
         }
         .....    
     };

问题是您需要实现person类的构造函数,请尝试以下代码:

#包括
#包括
#包括
使用名称空间std;
班主任{
公众:
字符串名;
人(){
}
人(字符串n){
name=n;
}
void setName(字符串k){
name=k;
}
字符串getName(){
返回名称;
}
};
班级学生:公众人士{
公众:
弦乐大调;
void setMajor(字符串m){
主修=m;
}
字符串getMajor(){
返回专业;
}
};
班主任:公众人士{
公众:
弦乐部;
学院(弦乐系){
部门=部门;
}
部门(字符串分离){
部门=出发;
}
字符串getDepartment(){
退货部;
}
};
int main(){
学生证;
s、 设置名称(“詹姆斯”);
s、 SET专业(“计算机科学”);
字符串p=s.getName();
字符串p2=s.getMajor();
库特
class person{
   public:
      string name;
      person();        //constructor only declared
      person(string n){
          name = n ;
     }
     .....    
 };
class person{
       public:
          string name;
          person(){}        //constructor implemented
          person(string n){
              name = n ;
         }
         .....    
     };
#include <iostream>
#include <string>
#include <cstdlib>
using namespace std;

class person{
    public:
        string name;
        person() {

        }
        person(string n){
            name = n ;
        }

        void setName(string k){
            name = k;
        }
        string getName(){
            return name;
        }
};
class student : public  person {
    public:
        string major;
        void setMajor(string m){
            major = m;
        }
        string getMajor(){
            return major;
        }
};
class faculty : public person{
    public:
        string department;
        faculty(string dept){
            department = dept;
        }
        void setDepartment(string depart){
            department = depart;
        }
        string getDepartment(){
            return department;
        }
};

int main() {

    student s;

    s.setName("james");
    s.setMajor("computer science");

    string p = s.getName();
    string p2 = s.getMajor();

    cout << "student name and mjor is :" << p << p2 << endl;
    faculty f("nanotech");
    f.setName("chris");
    f.setDepartment("electrical");
    string f1 = f.getName();
    string f2 = f.getDepartment();
    cout << "facult name and department :" << f1 << f2 << endl;

    return 0;
}