Question

我正在学习C ++课程。

这里我写了一个struct call Day。其中的每个功能都经过仔细检查

#ifndef _Day_h
#define _Day_h_
typedef struct Day {
    int year;
    int month;
    int date;
    void print()const;
    Day (int y,int m,int d);
    Day ();
    Day(const Day& day);
    void setYear(int y);
    void setMonth(int m);
    void setDate(int d);
    int getYear()const;
    int getMonth()const;
    int getDate()const;
} Day;
#endif

Day.h

#include<cstdio>
#include"Day.h"
using namespace std;
Day::Day(int y,int m,int d){
    year = y;
    month = m;
    date = d;
    void print();

}
Day::Day(const Day& day){
    this->year=day.year;
    this->month=day.month;
    this->date=day.date;
}
void Day::print()const{
    printf("%4d-%2d-%2d",year,month,date);
}
void Day::setYear(int y){
    this->year = y;
}
void Day::setMonth(int m){
    this->month = m;
}void Day::setDate(int d){
    this->date = d;
}
int Day::getYear()const{
    return this->year;
}
int Day::getMonth()const{
    return this->month;
}
int Day::getDate()const{
    return this->date;
}

在我检查之后，这应该没问题（也许）。

然后我写了另一堂课。

#ifndef _EMPLOYEE_H_
#include "Day.h"
#include <cstdio>
#include <iostream>
#include <string>
#include <typeinfo>
#define check_int(x) (typeid(x) != typeid(int) || ((x) <= 0))
#define check_str(s) (typeid((s)) != (typeid(std::string)))
#define NOH 10000
class Employee {
  private:
    int num;
    std::string name;
    bool sex; // true mean male false mean female
    Day birth;
    std::string job;

  public:
    Employee();
    Employee(int, std::string, bool, Day, std::string);
    void print()const;
    ~Employee();
};
#endif // !_EMPLOYEE_H_

Employee.h

#include"Employee.h"
#include "Day.h"
using namespace std;
Employee::Employee(int number, string nam, bool s, Day day1, string j): num(number), name(nam), sex(s), birth(day1), job(j) {}

void Employee::print() const {
    printf("编号: %d\n", this->num);
    cout << "姓名: " << this->name<<'\n';
    if (this->sex)
        printf("性别: 男\n");
    else
        printf("性别: 女\n");
    printf("生日: ");
    this->birth.print();
}

Employee.cpp

当我使用g++ Day.cpp Employee.cpp编译它们时然后来到这个

Employee.cpp:4:1: error: redefinition of ‘Employee::Employee(int, std::__cxx11::string, bool, Day, std::__cxx11::string)’
 Employee::Employee(int number, string nam, bool s, Day day1, string j): num(number), name(nam), sex(s), birth(day1), job(j) {}
 ^
Employee.h:42:1: note: ‘Employee::Employee(int, std::__cxx11::string, bool, Day, std::__cxx11::string)’ previously defined here
Employee.cpp:6:6: error: redefinition of ‘void Employee::print() const’
 void Employee::print() const {
      ^
Employee.h:65:6: note: ‘void Employee::print() const’ previously defined here

阅读了很多答案后，似乎是连接的问题。但经过长时间的检查，我找不到重新定义。

Answer 1

您忘记完成多次包含Employee.h的检查。您的文件以：

开头

#ifndef _EMPLOYEE_H_
#include "Day.h"

什么时候应该开始：

#ifndef _EMPLOYEE_H_
#define _EMPLOYEE_H_
#include "Day.h"

Answer 2

最后，我发现了我的问题。我纠正了我的代码中的错误。我的目录中有一个旧的.gch文件。我删除.gch文件后编译。问题解决了。谢谢大家帮帮我。

Answer 3

这不是完整的Employee标题，它说它在65行定义而你只粘贴了25行。你可能在Employee标题和employee.cpp中定义它

C ++：错误：重新定义类

3 个答案: