当我尝试使用类counter.cpp
运行该类时,出现以下错误
In file included from Bounded_Counter.h:7:0,
from counterApp.cpp:4:
Lower_Bounded_Counter.h:9:7: error: redefinition of âclass LowerBoundedCounterâ
Lower_Bounded_Counter.h:9:7: error: previous definition of âclass LowerBoundedCounterâ
In file included from Bounded_Counter.h:8:0,
from counterApp.cpp:4:
Upper_Bounded_Counter.h:9:7: error: redefinition of âclass UpperBoundedCounterâ
Upper_Bounded_Counter.h:9:7: error: previous definition of âclass UpperBoundedCounterâ
我知道我有两次上课,但我不知道如何找到它。你能帮我找一下我做错的事吗?有4个班级Counter.h, LowerBoundedCounter.h, UpperBoundedCounter.h,
和BoundedCounter.h
。 LowerBoundedCounter.h
和UpperBoundedCounter.h
都包含Counter.h
文件。 BoundedCounter.h
包含LowerBoundedCounter.h
和UpperBoundedCounter.h
个文件。实施文件为counterApp.cpp
(此处未提供)
这是Counter.h类。
#ifndef COUNTER_H
#define COUNTER_H
#include <iostream>
class Counter{
private:
int val;
public:
Counter():val(0) {}
Counter(int val):val(val){}
void up(){
this->val++;
}
void down(){
this->val--;
}
int getVal() const {
return this->val;
}
friend std::ostream &operator <<(std::ostream &os, const Counter &counter) {
os << "A Counter with a value of " << counter.val;
return os;
}
};
#endif
这是LowerBoundedCounter.h类。这个课程包含一个&#39; Counter&#39;对象
#ifndef LOWER_BOUNDED_COUNTER_H
#define LOWER_BOUNDER_COUNTER_H
#include<iostream>
#include "Counter.h"
class LowerBoundedCounter{
private:
Counter counter;
int limit;
public:
LowerBoundedCounter(int limit,int val):counter(val), limit(limit){
}
LowerBoundedCounter(int val):counter(val),limit(10){
}
LowerBoundedCounter():counter(),limit(0){
}
void up(){
if(getVal() > limit){
counter.up();
}
}
void down(){
counter.down();
}
int getLimit() const{
return this->limit;
}
int getVal() const{
return counter.getVal();
}
friend std::ostream &operator <<(std::ostream &os, const LowerBoundedCounter &LowerBoundedCounter){
os << "An LowerBoundedCounter with a value of " << LowerBoundedCounter.getVal() << " and a limit of "<<LowerBoundedCounter.limit;
return os;
}
};
#endif
这里是UpperBoundedCounter.h类
#ifndef UPPER_BOUNDED_COUNTER_H
#define UPPER_BOUNDER_COUNTER_H
#include<iostream>
#include "Counter.h"
class UpperBoundedCounter{
private:
Counter counter;
int limit;
public:
UpperBoundedCounter(int limit,int val):counter(val), limit(limit){
}
UpperBoundedCounter(int val):counter(val),limit(10){
}
UpperBoundedCounter():counter(),limit(10){
}
void up(){
if(getVal() < limit){
counter.up();
}
}
void down(){
counter.down();
}
int getLimit() const {
return this->limit;
}
int getVal() const{
return counter.getVal();
}
friend std::ostream &operator <<(std::ostream &os, const UpperBoundedCounter &UpperBoundedCounter){
os << "An UpperBoundedCounter with a value of " << UpperBoundedCounter.getVal() << " and a limit of "<<UpperBoundedCounter.limit;
return os;
}
};
最后,我在BoundedCounter.h
中有来自上述所有3个类的对象#ifndef BOUNDED_COUNTER_H
#define BOUNDER_COUNTER_H
#include<iostream>
#include "Counter.h"
#include "Lower_Bounded_Counter.h"
#include "Upper_Bounded_Counter.h"
class BoundedCounter{
private:
Counter counter;
UpperBoundedCounter upperBoundedCounter;
LowerBoundedCounter lowerBoundedCounter;
public:
BoundedCounter(int val, int upperLimit, int lowerLimit):counter(val),upperBoundedCounter(upperLimit),lowerBoundedCounter(lowerLimit){
}
BoundedCounter(int val,int upperLimit):counter(val), upperBoundedCounter(upperLimit), lowerBoundedCounter(){
}
BoundedCounter(int val):counter(val),upperBoundedCounter(),lowerBoundedCounter(){
}
BoundedCounter():counter(), upperBoundedCounter(), lowerBoundedCounter(){
}
void up(){
if(getVal() < upperBoundedCounter.getLimit() && getVal() > lowerBoundedCounter.getLimit()){
counter.up();
}
}
void down(){
counter.down();
}
int getLowerLimit() const{
return lowerBoundedCounter.getLimit();
}
int getUpperLimit() const{
return upperBoundedCounter.getLimit();
}
int getVal() const{
return counter.getVal();
}
friend std::ostream &operator <<(std::ostream &os, const BoundedCounter &BoundedCounter){
os << "An BoundedCounter with a value of " << BoundedCounter.getVal() << " and a lower limit of "<<BoundedCounter.getLowerLimit()
<<" and a higher limit of "<<BoundedCounter.getUpperLimit();
return os;
}
};
#endif
答案 0 :(得分:1)
您的标头保护宏在所有标头文件中都是错误的。
#ifndef BOUNDED_COUNTER_H
#define BOUNDER_COUNTER_H
Typo&#39; R&#39;
UpperBoundedCounter.h中存在一个较小的问题,它没有关闭#endif。但这会引起另一个问题。