C++类代码小样例

//编译一次
#pragma once

//防止重复引用
#ifndef CLS_USER_H
#define CLS_USER_H

//用到了printf
#include 

//struct和class关键字都可以
struct ClsUser
{
    private:
        int m_atr_UserId;//m_成员变量，atr_属性的缩写，配合WhoFeature的方式命名
    public:
        ClsUser();//无参数构造函数
        ClsUser(int in_UserId);//有参数构造函数
        ~ClsUser();//析构函数，释放内存，数值归0
        void mthd_setUserId(int in_UserId);//mthd_方法的缩写，用doSbSth的方式命名
        void mthd_getUserId();
};
#endif

#ifndef CLS_USER_C
#define CLS_USER_C
#include "ClsUser.h"

ClsUser::ClsUser(){
    ClsUser::m_atr_UserId = 0;
}
ClsUser::ClsUser(int in_UserId){
    ClsUser::m_atr_UserId = in_UserId;
}
ClsUser::~ClsUser(){
    ClsUser::m_atr_UserId = 0;
}
void ClsUser::mthd_setUserId(int in_UserId)
{
    ClsUser::m_atr_UserId = in_UserId;
}
void ClsUser::mthd_getUserId()
{
    printf("UserId:%dn", ClsUser::m_atr_UserId);
}
#endif

#include "ClsUser.h"

int main()
{
    ClsUser obj_user(1008611);//obj_对象前缀
    obj_user.mthd_setUserId(10086);//改变一开始的赋值为10086
    obj_user.mthd_getUserId();
    obj_user.~ClsUser();
    return 0;
}

编译语句

g++ -o ClsUserMain ClsUserMain.cpp ClsUser.cpp