下面是部分代碼

Worker.h

#include<string>

#include"Person.h"

using namespace std;

class Worker :public Person

{

public:

Worker(string code = "001", string color = "blue");

~Worker();

void carry();

protected:

string m_strCode;

};

Migrantworker.h

#include"Worker.h"

#include"Farmer.h"

class Migrantworker :public Farmer, public Worker

{

public:

Migrantworker(string name, string code, string color);

~Migrantworker();

};

Migrantworker.cpp

#include"Migrantworker.h"

#include<iostream>

using namespace std;

Migrantworker::Migrantworker(string name, string ncode, string color) :Farmer(name, color), Worker(code, color)

{

cout << "Migrantworker()" << endl;

}

Migrantworker::~Migrantworker()

{

cout << "~Migrantworker()" << endl;

}

我的代碼和老師一樣，為什么編譯錯誤？錯誤提示：黑體字code未聲明標識符,如何修改