Question

im的任务是让用户输入开始和停止时间，并计算和显示差异。我们需要一个头文件MyTime，其中包含带有小时，分钟和秒的结构。我的主要功能提示用户输入时间，它直接进入MyTime结构。然后，将调用DefineElapsedTime函数，并将两个指针传递给包含用户输入时间的两个结构，然后将其返回的指针存储在“指向MyTime的指针”变量中。那就是我遇到麻烦的地方。对此也给出了提示：“在DefineElapsedTime中声明一个静态MyTime结构，在其中存储经过的时间，然后返回其地址。返回指针或对自动对象的引用总是错误的。”

非常感谢您的帮助；我到目前为止所拥有的是下面。现在，我的调用DecisionElapsedTime函数的TimeDiff变量正在返回垃圾。我不确定我是否正确设置了结构。我是C ++的新手，因此深表感谢。谢谢。

主要功能：

#include <iostream>
#include "C1A7E1_MyTime.h"
using namespace std;

MyTime* DetermineElapsedTime(const MyTime* StartTime, const MyTime* StopTime);

int main()
{
    MyTime StartTime, StopTime;
    MyTime *TimeDiff;

    for (int i = 1; i <= 3; i++);
    {
        cout << "Please enter a Start and Stop Time that is space seperated on "
            "the same line in the following colon-delimited format "
            "(HH:MM:SS): ";

        // Declare Colon delimiters
        char Colon1, Colon2, Colon3, Colon4;

        // Get users input
        cin >> StartTime.hours >> Colon1 >> StartTime.minutes >> Colon2
            >> StartTime.seconds >> StopTime.hours >> Colon3
            >> StopTime.minutes >> Colon4 >> StopTime.seconds;

        TimeDiff = DetermineElapsedTime(&StartTime, &StopTime);

        cout << "\nThe time elapsed from " << StartTime.hours << Colon1
            << StartTime.minutes << Colon2 << StartTime.seconds << " to "
            << StopTime.hours << Colon3 << StopTime.minutes
            << Colon4 << StopTime.seconds << " is " << TimeDiff;
    }
    return 0;
}

DetermineElapsedTime函数：

#include "C1A7E1_MyTime.h"
#define HR_SECONDS 3600;
#define MIN_SECONDS 60;
using namespace std;

MyTime *DetermineElapsedTime(const MyTime *StartTime, const MyTime *StopTime)
{
    // Declare static MyTime structure to store elapsed time in
    MyTime static ElapsedTime;

    // Pull out Start Time in seconds
    long int Start_Hr = StartTime->hours * HR_SECONDS;
    int Start_Min = StartTime->minutes * MIN_SECONDS;
    int Start_Sec = StartTime->seconds;

    // Total the number of seconds in start time
    int TotalStart = Start_Hr + Start_Min + Start_Sec;

    // Pull out Stop Time in seconds
    long int Stop_Hr = StopTime->hours * HR_SECONDS;
    int Stop_Min = StopTime->minutes * MIN_SECONDS;
    int Stop_Sec = StopTime->seconds;

    // Total the number of seconds in stop time
    int TotalStop = Stop_Hr + Stop_Min + Stop_Sec;
    
    // Find the difference in start/stop time
    long int TimeDiff = (TotalStop - TotalStart);
    
    // If stop time is less than start time (new day) then make it positive
    if (TimeDiff <= 0)
    {
        TimeDiff = -TimeDiff;
    }
    
    // Find time difference in hours
    int ElapsedHr = TimeDiff / HR_SECONDS;
    ElapsedTime.hours = ElapsedHr;

    // Find time difference in minutes
    int FirstSub = ElapsedHr * HR_SECONDS;
    int remainingSeconds = (TimeDiff) - FirstSub;
    int ElapsedMin = remainingSeconds / MIN_SECONDS;
    ElapsedTime.minutes = ElapsedMin;

    // Find time difference in seconds
    int SecondSub = ElapsedMin * MIN_SECONDS;
    remainingSeconds = remainingSeconds - SecondSub;
    int ElapsedSec = remainingSeconds;
    ElapsedTime.seconds = ElapsedSec;

    //Return address of elapsed time
    return(&ElapsedTime);
}

MyTime结构/头文件

#ifndef C1A7E1_MYTIME_H // Header Guard
#define C1A7E1_MYTIME_H

//Structure Definition and declaration of structur variables
struct MyTime
{
    int hours, minutes, seconds;
};

#endif

声明静态结构并返回其地址，而不是指针或引用？

0 个答案: