CISC181, Practice With Classes

In both cases, write the complete class declaration
as a .h file, and defintions for all member
functions as a .cc file.

Just for today: all member function definitions in the
 .cc file, and the function prototypes for member
 functions in the .h 
 file (along with the declaration of data members.)

 (Yes, it is possible to do function defs 
 inside the class .h file but for today, we won't).

Be sure to use pre-processor directives to make
your .h file idempotent.

Be sure to use "const" on all member functions
where it is appropriate.

(1) Write a class to represent a point in the
    Cartesian plane.  Represent x and y as double.

    Include 
    *  a constructor that initializes the point to
       the origin 
    * set and get functions for x and y
      
    Also include a function distFromOrigin() the
    returns the distance from the origin, and a
    function that returns the angle of that point
    in radians (both functions should return
    double.)

(2) Write a class to represent a time of day 
    (hours and minutes).

  Include a constructor that takes an integer # of
  hours, and integer # of minutes in military time
  (e.g. 13:25 represents the start time for the
  010-012 section lecture, and 14:30 represents the
  start time of the 013-015 section lecture.)

  Include set and get functions for hour and
  minute.

  The setHour() function and setMinute() functions
  should return bool--- return true if the
  parameter values were valid and the attribute was
  set, and return false if the parameter values
  were NOT valid, and the attribute was NOT set.

  For the constructor, if invalid values were
  passed in, just set the value of the time to
  00:00 (i.e. midnight).



(3) Suppose I had the following files, related to
question 2 above.

  timeOfDay.cc
  timeOfDay.h
  main.cc

How would I compile these into a useful program?

Suppose that main.cc contains the following:

// main.cc  An example of USING the time class

#include <iostream>
using namespace std;

#include "timeOfDay.h"

int main(void)
{

  // each of these invokes the constructor

  TimeOfDay_C dinnerTime(18,30); // dinner is at 6:30pm

  TimeOfDay_C breakfast(08,15); // breakfast is at 8:15am

  TimeOfDay_C officeHrsStart(15, 45); // breakfast is at 8:15am

  cout << "If I call getHours on officeHrsStart, I get: "
       << officeHrsStart.getHours() << endl;

  return 0;

}


Answer:

   I need to compile the .cc files separately,
and then link them together into an executable.

To compile the .cc files separately do:

  CC -c timeOfDay.cc
  CC -c main.cc

To link the two together, do:

  CC timeOfDay.o main.o -o main

The thing that follows the -o should be the name of
executable file that you want to create.  It typically
is called by the same name as the .cc file that contains
the 
   "int main(void)" line
    or the "int main(int argc, char *argv[]) line.



(4) Suppose I wanted to create a Makefile to go along with
timeOfDay.cc and main.cc.   What would it look like?

Answer: See the file "Makefile" in the current directory for an answer.