[C++]

Update the program that is already provided for the Digital Time class to add a new member function that computes the difference in time between two different DigitalTime objects.

Three files are already provided for you:

dtime.h a header file that defines the digital time class dtime.cpp the implementation code for the digital time class

C++DigitalTimeApplication.cpp sample code that tests the digital time class

LAB ASSIGNMENT: 2) Refer to practice problem #1 (8th Edition page 718 , 9th Edition page 736) for additional information. void DigitalTime::interval_since(const DigitalTime& a_previous_time, int& hours_in_inteval, int& minutes_in_interval) const

where: hours_in_interval and minutes_in_interval are values returned using PassByReference.

Refer to C++DigitalTimeApplication.cpp to see a sample run of the program. The project is not complete until the code for the interval_since member function has been written. Add the the interval_since member function and test it a) when the first argument is earlier in the day than the second argument and b) when the first argument is later in the day than the first argument. In this case, the time given as the first argument is assumed to be on the previous day.

#pragma once //DISPLAY 12.2 Implementation File for DigitalTime //Implementation file dtime.cpp (Your system may require some //suffix other than .cpp): This is the IMPLEMENTATION of the ADT DigitalTime. //The interface for the class DigitalTime is in the header file dtime.h. #include "stdafx.h" //DISPLAY 12.1 Interface File for DigitalTime //Header file dtime.h: This is the INTERFACE for the class DigitalTime. //Values of this type are times of day. The values are input and output in //24-hour notation, as in 9:30 for 9:30 AM and 14:45 for 2:45 PM. #include  using namespace std; class DigitalTime { public: friend bool operator ==(const DigitalTime& time1, const DigitalTime& time2); //Returns true if time1 and time2 represent the same time; //otherwise, returns false. DigitalTime(int the_hour, int the_minute); //Precondition: 0 <= the_hour <= 23 and 0 <= the_minute <= 59. //Initializes the time value to the_hour and the_minute. DigitalTime( ); //Initializes the time value to 0:00 (which is midnight). void advance(int minutes_added); //Precondition: The object has a time value. //Postcondition: The time has been changed to minutes_added minutes later. void advance(int hours_added, int minutes_added); //Precondition: The object has a time value. //Postcondition: The time value has been advanced //hours_added hours plus minutes_added minutes. friend istream& operator >>(istream& ins, DigitalTime& the_object); //Overloads the >> operator for input values of type DigitalTime. //Precondition: If ins is a file input stream, then ins has already been //connected to a file. friend ostream& operator <<(ostream& outs, const DigitalTime& the_object); //Overloads the << operator for output values of type DigitalTime. //Precondition: If outs is a file output stream, then outs has already been //connected to a file. void interval_since(const DigitalTime& previous_time, int& hours_in_interval, int& minutes_in_interval) const; //Precondition: The object has a time value. //Precondition: The previous_time object has a time value //Postcondition: The hours_in_interval indicates the number of hours that have passed //Postcondition: The minutes_in_interval indicates the number of minutes that have passed private: int hour; int minute; }; 

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#include "stdafx.h" //DISPLAY 12.2 Implementation File for DigitalTime //Implementation file dtime.cpp (Your system may require some //suffix other than .cpp): This is the IMPLEMENTATION of the ADT DigitalTime. //The interface for the class DigitalTime is in the header file dtime.h. #include  #include  #include  #include "dtime.h" using namespace std; //These FUNCTION DECLARATIONS are for use in the definition of //the overloaded input operator >>: void read_hour(istream& ins, int& the_hour); //Precondition: Next input in the stream ins is a time in 24-hour notation, //like 9:45 or 14:45. //Postcondition: the_hour has been set to the hour part of the time. //The colon has been discarded and the next input to be read is the minute. void read_minute(istream& ins, int& the_minute); //Reads the minute from the stream ins after read_hour has read the hour. int digit_to_int(char c); //Precondition: c is one of the digits '0' through '9'. //Returns the integer for the digit; for example, digit_to_int('3') returns 3. bool operator ==(const DigitalTime& time1, const DigitalTime& time2) { return (time1.hour == time2.hour && time1.minute == time2.minute); } //Uses iostream and cstdlib: DigitalTime::DigitalTime(int the_hour, int the_minute) { if (the_hour < 0 || the_hour > 23 || the_minute < 0 || the_minute > 59) { cout << "Illegal argument to DigitalTime constructor."; exit(1); } else { hour = the_hour; minute = the_minute; } } DigitalTime::DigitalTime( ) : hour(0), minute(0) { //Body intentionally empty. } void DigitalTime::advance(int minutes_added) { int gross_minutes = minute + minutes_added; minute = gross_minutes%60; int hour_adjustment = gross_minutes/60; hour = (hour + hour_adjustment)%24; } void DigitalTime::advance(int hours_added, int minutes_added) { hour = (hour + hours_added)%24; advance(minutes_added); } //Uses iostream: ostream& operator <<(ostream& outs, const DigitalTime& the_object) { outs << the_object.hour << ':'; if (the_object.minute < 10) outs << '0'; outs << the_object.minute; return outs; } //Uses iostream: istream& operator >>(istream& ins, DigitalTime& the_object) { read_hour(ins, the_object.hour); read_minute(ins, the_object.minute); return ins; } int digit_to_int(char c) { return ( static_cast(c) - static_cast('0') ); } //Uses iostream, cctype, and cstdlib: void read_minute(istream& ins, int& the_minute) { char c1, c2; ins >> c1 >> c2; if (!(isdigit(c1) && isdigit(c2))) { cout << "Error illegal input to read_minute "; exit(1); } the_minute = digit_to_int(c1)*10 + digit_to_int(c2); if (the_minute < 0 || the_minute > 59) { cout << "Error illegal input to read_minute "; exit(1); } } //Uses iostream, cctype, and cstdlib: void read_hour(istream& ins, int& the_hour) { char c1, c2; ins >> c1 >> c2; if ( !( isdigit(c1) && (isdigit(c2) || c2 == ':' ) ) ) { cout << "Error illegal input to read_hour "; exit(1); } if (isdigit(c1) && c2 == ':') { the_hour = digit_to_int(c1); } else //(isdigit(c1) && isdigit(c2)) { the_hour = digit_to_int(c1)*10 + digit_to_int(c2); ins >> c2;//discard ':' if (c2 != ':') { cout << "Error illegal input to read_hour "; exit(1); } } if ( the_hour < 0 || the_hour > 23 ) { cout << "Error illegal input to read_hour "; exit(1); } } void DigitalTime::interval_since(const DigitalTime& previous_time, int& hours_in_interval, int& minutes_in_interval) const { // you need to complete this part of the program to compute the // a) hours_in_interval, and // b) minutes_in_interval hours_in_interval = 0; minutes_in_interval = 0; return; } 

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// // You need to complete the member function interval_since before the project is finished // // C++ADTclassDigitalTime.cpp : Defines the entry point for the console application. #include "stdafx.h" // for Microsoft C++ only #include "dtime.h" #include  using namespace std; int main(int argc, char* argv[]) { // create a DigitalTime object and name it time1 DigitalTime time1(14,22); // initialize time to 14:22 (2:44pm) cout << "The starting time should be 14:22:" << endl; cout << time1 << endl << endl; // display the time cout << "Advance by 32 minutes. The result should be 14:54" << endl; time1.advance(32); // add 32 minutes. Should be 14:54 cout << time1 << endl << endl; // display the time cout << "Advance by 1 hour, 30 minutes. The result should be 16:14" << endl; time1.advance(1,20); // add 1 hour, 30 minutes. Should be 16:14 cout << time1 << endl << endl; // display the time cout << "Input a new time "; cin >> time1; cout << time1 << endl << endl; // display the time cout << "Advance by 5 minutes" << endl; time1.advance(5); // advance 5 minutes cout << time1 << endl << endl; // display the time // // You need to complete the member function interval_since before the project is finished // cout << "You need to complete the program to display elapsed time" << endl; int hours, minutes; DigitalTime time2(8, 25); DigitalTime time3(14, 0); DigitalTime time4(22, 0); // the time difference between 8:25 and 14:00 (2:00pm) should be 5 hours, 35 minutes time3.interval_since(time2, hours, minutes); cout << "The time difference between " << time2 << " and " << time3 << " is " << hours << " hours and " << minutes << " minutes" << endl; // the time difference between 22:00(10pm) and 8:25 is 10 hours 25 minutes time2.interval_since(time4, hours, minutes); cout << "The time difference between " << time4 << " and " << time2 << " is " << hours << " hours and " << minutes << " minutes" << endl; }