c – 链接器错误LNK2001

Customer bob("Bob","25 Bob Lane","01bob82","M","bob/bob/bob");

这一行给出了这个错误：

Error   1   error LNK2001: unresolved external symbol "public: __thiscall
Customer::Customer(class std::basic_string<char,struct std::char_traits<char>,class
std::allocator<char> >,class std::basic_string<char,class 
std::allocator<char> >,class
std::allocator<char> >)" (??0Customer@@QAE@V?$basic_string@DU?$char_traits@D@std@@V?
$allocator@D@2@@std@@0000@Z)    D:DropboxWorkC++C++ AssignmentC++ 
Assignmentdriver.obj

包含构造函数的Customer类：

#pragma once
#include "l_list.h"
#include "Account.h"
#include <string>

using namespace std;

class Customer
{
private:
    l_list<Account> accounts;
    string name;
    string address;
    string telNo;
    string sex;
    string dob;

public:
    Customer(string name,string address,string telNo,string sex,string dob)
    {
        Customer::name = name;
        Customer::address = address;
        Customer::telNo = telNo;
        Customer::sex = sex;
        Customer::dob = dob;
    }

    void createAccount()
    {
        cout << "What type of account?";

    }

};