[英]error: use of undeclared identifier "classname"
我正在尝试实施 class“时间”。 我已将所有声明放在 Time.h 中,将实现放在 Time.cpp 中。 然后我在一个单独的文件 Test.cpp 中测试它。 编译 Time.cpp 文件时,出现此错误error: use of undeclared identifier 'Time'
。 这是代码,
时间.h
#ifndef _TIME_H_
#define _TIME_H_
#include <iostream>
class Time
{
public:
Time();
// extra constructor not provided in part 3
Time(int hour, int min = 0, int h = 0);
void setTime(int h, int m, int s);
Time operator+(unsigned int n) const;
Time& operator+=(unsigned int n);
Time& operator++(); // prefix version
Time operator++(int n); // postfix version
// member functions you have to implement
bool operator==(const Time &t) const;
bool operator!=(const Time &t) const;
bool operator<(const Time &t) const;
bool operator<=(const Time &t)const;
Time operator-(unsigned int n) const;
Time& operator-=(unsigned int n);
Time& operator--(); // prefix version
Time operator--(int n); // postfix version
int getHour() const;
int getMin() const;
int getSec() const;
private:
int hour, min, sec;
// output in universal format
friend ostream& operator<<(ostream& o, const Time& t);
// new friend functions you have to implement
friend bool operator>(const Time& t1, const Time& t2);
friend bool operator>=(const Time& t1, const Time& t2);
friend int operator%(const Time& t1, const Time& t2);
};
#endif
时间.cpp
#include <iostream>
#include <iomanip>
#include <cmath>
#include "Time.h"
using namespace std;
Time::Time()
{
hour = min = sec = 0;
}
Time::Time(int h, int m, int s)
{
setTime(h, m, s);
}
void Time::setTime(int h, int m, int s)
{
hour = (h>=0 && h<24) ? h : 0;
min = (m>=0 && m<60) ? m : 0;
sec = (s>=0 && s<60) ? s : 0;
}
int Time::getHour() const
{
return hour;
}
int Time::getMin() const
{
return min;
}
int Time::getSec() const
{
return sec;
}
Time& Time::operator+=(unsigned int n)
{
sec += n;
if (sec>=60)
{
min += sec/60;
sec %= 60;
if (min>=60)
{
hour = (hour + min/60)%24;
min %= 60;
}
}
return *this;
}
Time& Time::operator-=(unsigned int n)
{
sec -= n;
if (sec < 0)
{
min -= ceil((sec * (-1)) / 60.0);
sec %= 60;
if (sec < 0)
{
sec += 60;
}
if (min < 0)
{
hour -= ceil((min * (-1)) / 60.0);
min %= 60;
if (min < 0)
{
min += 60;
}
}
}
return *this;
}
Time Time::operator+(unsigned int n) const
{
Time tCopy(*this);
tCopy += n;
return tCopy;
}
Time Time::operator-(unsigned int n) const
{
Time tCopy(*this);
tCopy -= n;
return tCopy;
}
Time& Time::operator++() // prefix version
{
*this += 1;
return *this;
}
Time& Time::operator--() // prefix version
{
*this -= 1;
return *this;
}
Time Time::operator++(int n) // postfix version
{
Time tCopy(*this);
*this += 1;
return tCopy;
}
Time Time::operator--(int n) // postfix version
{
Time tCopy(*this);
*this -= 1;
return tCopy;
}
bool Time::operator==(const Time &t) const
{
if(hour == t.getHour() && min == t.getMin() && sec == t.getSec())
{
return true;
}
return false;
}
bool Time::operator!=(const Time &t) const
{
if(*this == t)
{
return false;
}
return true;
}
bool Time::operator<(const Time &t) const
{
if(hour < t.getHour() || min < t.getMin() || sec < getSec())
{
return true;
}
return false;
}
bool Time::operator<=(const Time &t)const
{
if(*this < t || *this == t)
{
return true;
}
return false;
}
ostream& operator<<(ostream& o, const Time &t)
{
o << setfill('0') << setw(2) << t.hour << ":" << setw(2) << t.min << ":" << setw(2) << t.sec;
return o;
}
bool operator>(const Time& t1, const Time& t2)
{
if(t1 < t2 || t1 == t2)
{
return false;
}
return true;
}
bool operator>=(const Time& t1, const Time& t2)
{
if(t1 < t2)
{
return false;
}
return true;
}
int operator%(const Time& t1, const Time& t2)
{
int totalSec = 24 * 60 * 60;
int earlyTime = (t1.getHour() * 3600) + (t1.getMin() * 60) + (t1.getSec());
int lateTime = (t2.getHour() * 3600) + (t2.getMin() * 60) + (t2.getSec());
if(earlyTime <= lateTime)
{
return lateTime - earlyTime;
}
else
{
return (totalSec - earlyTime) + lateTime;
}
}
代码有什么问题?
Time
是一个过于笼统的术语。 _TIME_H_
可能由其中一个系统定义,并且在预处理过程中会跳过您的 header。
如果您使用-save-temps
运行编译器,它会将预处理器 output 保留在名为Time.ii
的文件中。 您将能够看到编译器没有看到Time.h
中的任何代码。
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