time.cpp

《c＋＋大学教程实验指导书》源码

// time.cpp
// member function definitions for time.cpp
#include <iostream> 

using std::cout; 

#include <ctime>

#include "time.h"

// constructor
Time::Time()
{
   long int totalTime;            // time in seconds since 1970
   double currentYear = 2002 - 1970; // current year
   double totalYear;              // current time in years
   double totalDay;               // days since beginning of year
   double divisor;                // conversion divisor
   int timeShift = 4;         // time returned by time() is
                                  // given as the number of seconds
                                  // elapsed since 1/1/70 GMT.
                                  // Depending on the time zone
                                  // you are in, you must shift
                                  // the time by a certain 
                                  // number of hours. For this
                                  // problem, 4 hours is the 
                                  // current shift for EST.
   double tempHour;
   double tempMinute;             // Used in conversion to seconds.
   double tempSecond;             // Used to set seconds.
   
   totalTime = time( NULL );
   
   divisor = 60 * 60 * 24 * 365;
   
   totalYear = totalTime / divisor - currentYear;
   
   totalDay = 365 * totalYear; // leap year unimportant
                               // for hour/minute/seconds
                               // calculation
   
   tempHour = 
      (totalDay - static_cast< int >( totalDay ) ) * 24;
      
   tempMinute = 
      ( tempHour - static_cast< int >( tempHour ) ) * 60; 
      
   tempSecond = 
      ( tempMinute - static_cast< int >( tempMinute ) ) * 60; 

   
   setHour( static_cast< int >( tempHour ) - timeShift );
   setMinute( static_cast< int >( tempMinute ) );
   setSecond( static_cast< int >( tempSecond ) );   

} // end class Time constructor

// function printStandard definition
void Time::printStandard()
{
   cout << ( ( hour % 12 == 0 ) ? 12 : hour % 12 ) << ':'
        << ( minute < 10 ? "0" : "" ) << minute << ':'
        << ( second < 10 ? "0" : "" ) << second << '\n';

} // end function printStandard


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