A Diary Gone Nuts

Hi, as part of my course at uni we have started to learn C++. One of the projects we are working on is a diary. Its supposed to do the following:

The Diary objects created in previous weeks were hardly realistic as they had either a single meeting object inside or a single day containing an array of meetings. This practical attempts to build a more realistic diary having 365/6 day objects built in (depending on leap year or not), each with the capability of holding a variable number of meetings and having the ability to both add and delete meetings.

The new Diary class will provide the following :-

* A constructor specifying the year for the diary as an integer
* An addMeeting function/method which specifies a meeting object and the date of the meeting
* A deleteMeeting function/method which specifies the date and time of the meeting to be removed
* A display function/method which specifies the date and displays all meetings on that day
* A displayFirst function/method which specifies a date and displays the first meeting on that day or returns an empty string if none
* A displayNext function/method which specifies the date and displays the next meeting on that date or returns an empty string if no more

The day class should be revised to provide for the following :-

* A variable number of meeting objects - using a Vector collection class rather than an array
* Meetings should be added in time of day order
* If an attempt to add a meeting starting at the same time as another on any given day, this should not be allowed and an error signalled to the user
* Meetings may overlap but an error message should be displayed to the user

The meeting class should be revised to provide for the following :-

* A function/method to return the start time of the meeting (e.g. in minutes from midnight)
* A function/method to return the duration of the meeting


The part i'm having trouble with at the moment is related to addingmeetings. Even when meetings do not overlap the user is given a message informing them that they do. I was hoping that someone could point out where my logic was failing. The add meeting function is in day.cpp.

Thanks in advance for any help!!

the other files...

I'm feeling quite lazy. What file is the code for addingMeetings in?

Code:

---

if(new_end > meeting->start_time())
        clash = true;

---

Here, you are checking the to-be-added meeting against itself. Rather, you should check the to-be-added meeting against appointment.at(i).

so it should be

if(new_end > appointments.at(i)->start_time())
clash = true;
}

if ive understood you??

The add meeting function is in day.cpp.

Quote:

---

Originally Posted by chris Ray

so it should be

if(new_end > appointments.at(i)->start_time())
clash = true;
}

if ive understood you??

---

Right.

In that case i still get a clash error, i'm so confused :-( sorry!!

With what data do you get an error?

Please enter your Name: chris
Please enter Year for Diary (YYYY): 2008
Simple Diary
1) Add Meetings
2) Delete Meeting
3) Display All
4) Display One by One
5) Exit
Please choose an option: 1

Enter name of person, type end to quit: jim
Enter location: uni
Enter subject: C
Enter time (hour): 10
Enter time (mins): 00
Enter duration(mins): 10
Enter Month (MM) : 10
Enter Day of Month (DD): 10
looking at 283start time = 600
here
Succeded

Enter name of person, type end to quit: bob
Enter location: home
Enter subject: tea
Enter time (hour): 10
Enter time (mins): 30
Enter duration(mins): 10
Enter Month (MM) : 10
Enter Day of Month (DD): 10
looking at 283start time = 630
here
start time = 630
start time = 600
start time = 630
start time = 600
start time = 600
start time = 630
start time = 600
start time = 630
Meeting Clashed, but added

Enter name of person, type end to quit:

The first meeting should finish at 10:10 and the second starts at 10:30 and finishes at 10:40, there should not be a clash!!

First curious thing, why does diary.h include diary.h ?

First bad thing, meeting.h has using namespace std;
Putting "using" inside a header file forces the namespace onto anyone who includes the file. And if they didn't want all of the std namespace, there is no way out.
You should have std::string in the header fle, and no "using" statement.

First wrong thing.
if(clash = false)
What's the difference between = and == ?

Second wrong thing:

Code:

---

bool Diary::delete_meeting(tm date, int hour, int min)
{
  if(day[date.tm_yday] == NULL)
  {
    return "No meetings on this Date";

---

I'm quite sure that you shouldn't be returning a string (well, a const char* in effect) from a function that returns bool. :)

Another strange thing:

Code:

---

string Day::display_first()
{
  position = 1;
  return appointments[1]->display();
}

---

I'm too lazy to figure out if that's actually what you want, but keep in mind that [0] is the first element in arrays and array-like things in C++. (And what if there are no appointments?)

Another probably bad thing:

Code:

---

    delete &appointments.at(i);           
// ...
      delete appointments.at(i); //remove object

---

I imagine that one of those statements isn't as it should be.

Another strange thing:

Code:

---

Diary::~Diary()
{
  delete[]day;             
}

---

Are you sure you want to delete an array that was never dynamically allocated with new? (Hint: no, you don't want to.)

Firstly thanks for all the help, i'm making some progress now!!

Right a quick update:

I added the missing = sign in the if checking for clashes. i can now add meetings without a problem!!

Should this become a string?

Code:

---

string Diary::delete_meeting(tm date, int hour, int min)

bool Diary::delete_meeting(tm date, int hour, int min)
{
  if(day[date.tm_yday] == NULL)
  {
    return "No meetings on this Date";

---

You made a good point about the first element in the array being 0 and not 1 so the display first function now works quite well.

Can you explain a bit more about this line???

Code:

---

    delete &appointments.at(i);           
// ...
      delete appointments.at(i); //remove object

---

I have changed this to read

Code:

---

Diary::~Diary(){
 
}

---

All i really need to get working now is the display all function, so any help with this would be great!!

If you want an updated bunch of source files they can be found at this address:

Code:

---

www.rayjchris.co.uk/simplediary.zip

---

Quote:

---

Originally Posted by chris Ray

Should this become a string?

Code:

---

string Diary::delete_meeting(tm date, int hour, int min)

bool Diary::delete_meeting(tm date, int hour, int min)
{
  if(day[date.tm_yday] == NULL)
  {
    return "No meetings on this Date";

---

---

Probably not. You don't really expect a delete_meeting function to return a string; a bool makes sense here. Just make sure you return either true or false, depending on whether the function succeeded in deleting the meeting or not, and not a string!

Quote:

---

Can you explain a bit more about this line???

Code:

---

    delete &appointments.at(i);           
// ...
      delete appointments.at(i); //remove object

---

---

I was just indicating that, since those two lines were referring to the same variable, there's probably something wrong with one of them. You're deleting the .at() directly in one, and the address of the .at() in the other.

Looking at your source code again, it seems to me that this version

Code:

---

delete appointments.at(i);

---

is the proper one, since appointments is a vector of pointers.

I find it a little bizzare that the variable in main() for storing a year is called "hour"! :)

What if Day::display_first()'s if fails? You won't be returning anything at all . . . .

Also, having "using namespace std" in a header file isn't the best idea. Search the forums for why.