C++虚函数问题

Question

我需要用 C++ 编写一些东西。我对虚函数有疑问。

例如，在头文件 Human.h 中我有这个:

class Human
{
    public:
        virtual int Age();
        Human();
        ~Human();
}

在 Human.cpp 文件中我有这个:

#include<iostream>
#include "Human.h"

int Human::Age()
{
    return 0;
}

我得到这些编译错误:

Error    4    error C2371: 'Human::Age' : redefinition; different basic types    c:\users\jan\desktop\testc\testc\human.cpp    5    1    TestC
Error    3    error C2556: 'Human Human::Age(void)' : overloaded function differs only by return type from 'int Human::Age(void)'    c:\users\jan\desktop\testc\testc\human.cpp    5    1    TestC
Error    2    error C2628: 'Human' followed by 'int' is illegal (did you forget a ';'?)    c:\users\jan\desktop\testc\testc\human.cpp    4    1    TestC

Answer 1

您忘记以 ; 结束类定义

应该是

class Human
{
public:
    virtual int Age();
    Human();
    ~Human();
};

这可能会使错误消失。另外，请始终阅读编译器的输出:Error 2 error C2628: 'Human' followed by 'int' is illegal (did you forget a ';'?) c:\users\jan\desktop\testc\testc\human.cpp 4 1 TestC