Segmentation Fault while passing a pointer array of classes [closed] - c++

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I am having a fairly frustrating issue where I attempt to pass the contents of a pointer array that is filled with objects to another class so that I may print the contents of the Array but no matter what I have tried to do in changing the way I pass the array I consistently get a Segmentation Fault. I have looked all around for people with similar problems and I did not manage find anyone with the same issue but still I apologize if this is a duplicate question!
anyways, my code for these two classes is
#include <iostream>
#include <vector>
#include <string>
using namespace std;
//Time Class
class Time{
public:
Time();
void setHour(int sHour){hour = sHour;}
void setMinute(int sMinute){minute = sMinute;}
void setAmPm(int sAmPm){ampm = sAmPm;}
int getHour(){return hour;}
int getMinute(){return minute;}
int getAmPm(){return ampm;}
private:
int hour;
int minute;
int ampm;
};
//Time Constructor implementation
Time::Time(){
hour = 0;
minute = 0;
ampm = 0;
}
//Event Class
class Event{
public:
Event(string x, Time y);
void setDesc(string sDesc){description = sDesc;}
string getDesc(){return description;}
void setTime(Time t, int h, int m, int ampm){t.setHour(h); t.setMinute(m); t.setAmPm(ampm);}
Time getTime(){return eventTime;}
printEvent(Event e){
Time t = e.getTime();
cout << description << endl;
string ampm ="";
if(t.getAmPm() == 0)
ampm = "AM";
else
ampm = "PM";
cout << t.getHour() << ":" << t.getMinute() << " in the " << ampm;
}
private:
string description;
Time eventTime;
};
//Event Constructor implementation
Event::Event(string cDesc, Time t){
description = cDesc;
eventTime = t;
}
//Month Class
class Month{
public:
Month(string x, int y);
void addEvent(string desc, int h, int m, int ampm, int day){
Time t;
t.setHour(h);
t.setMinute(m);
t.setAmPm(ampm);
Event e(desc, t);
this -> event[day] = &e;
}
void deleteEvent(int day){delete event[day];}
Event getEvent(int day){
return *event[day];
}
void displayEvent(int day){
Event e = getEvent(day);
e.printEvent(e);
}
void displayAll(int days){
// Time t;
// Event e("StupidSolution", t);
// for(int i = 0; i < days; i++)
// e.printEvent(*event[i]);
}
private:
int days;
string month;
Event* event[31];
};
//Month Constructor implementation
Month::Month(string cMonth, int cDays){
days = cDays;
month = cMonth;
}
//both num days and find month are used to determine the Month the user wants to generate a calendar for and the amount of days in that month
string findMonth(int numMonth){
if(numMonth == 1)
return "January";
if(numMonth == 2)
return "February";
if(numMonth == 3)
return "March";
if(numMonth == 4)
return "April";
if(numMonth == 5)
return "May";
if(numMonth == 6)
return "June";
if(numMonth == 7)
return "July";
if(numMonth == 8)
return "August";
if(numMonth == 9)
return "September";
if(numMonth == 10)
return "October";
if(numMonth == 11)
return "November";
if(numMonth == 12)
return "December";
}
int numDays(int numMonth){
if(numMonth == 1)
return 31;
if(numMonth == 2)
return 28;
if(numMonth == 3)
return 31;
if(numMonth == 4)
return 30;
if(numMonth == 5)
return 31;
if(numMonth == 6)
return 30;
if(numMonth == 7)
return 31;
if(numMonth == 8)
return 31;
if(numMonth == 9)
return 30;
if(numMonth == 10)
return 31;
if(numMonth == 11)
return 30;
if(numMonth == 12)
return 31;
}
//gets all necessary info from user for creating a new event
void newEvent(int day, Month month){
string desc = "";
int h = 0;
int m = 0;
int ampm = 0;
cin.get();
cout << "Please enter a Brief Description of the Event!: " << endl;
getline(cin, desc);
cout << "Please enter the Hour of event(1-12): " << endl;
cin >> h;
cout << "Please enter the Minute of event (0-59): " << endl;
cin >> m;
cout << "Please enter 0 if it is in the AM and 1 if it is in the PM: " << endl;
cin >> ampm;
month.addEvent(desc, h, m, ampm, day);
}
int main(void){
string month = "";
int numMonth = 0;
int menuChoice = 0;
int menuLoop = 0;
int days = 0;
int eDay = 0;
cout << "please enter the month you would like to track(1-12): ";
cin >> numMonth;
days = numDays(numMonth);
month = findMonth(numMonth);
Month m(month,days);
while(menuLoop == 0){
cout << "Event Calendar for the month of " << month << endl;
cout << "1. Create a new Event" << endl;
cout << "2. Delete an existing Event" << endl;
cout << "3. Display Event for a particular day" << endl;
cout << "4. Display All Events" << endl;
cout << "5. Exit Program" << endl;
cout << "Enter Choice: " << endl;
cin >> menuChoice;
switch(menuChoice){
case 1:
cout << "What day would you like this event to be on?" << endl;
cin >> eDay;
if(eDay > 0 && eDay <= days)
newEvent(eDay, m);
else cout << "Invalid Day";
break;
case 2:
cout << "What day would you like to clear of events?" << endl;
cin >> eDay;
if(eDay > 0 && eDay <= days)
m.deleteEvent(eDay);
break;
case 3:
cout << "What day would you like to View?" << endl;
cin >> eDay;
if(eDay > 0 && eDay <= days)
m.displayEvent(eDay);
break;
case 4:
cout << "Displaying all Events.";
m.displayAll(days);
break;
case 5:
cout << "Goodbye!" << endl;
menuLoop++;
break;
default:
cout << "incorrect input";
break;
}
}
}
The important bits are the Event* event[31]; array, the displayEvent and the PrintEvent functions. I have tried all forms of passing by reference and de-referencing the array as I pass it but nothing seems to fix the issue...
Thank you so much!
Edit: added the remainder of the program, the segmentation fault occurred after creating a new event (option 1 on the menu) then either trying to delete it (option 2) or display it (option 3)

Answer 1

This function:
void addEvent(string desc, int h, int m, int ampm, int day){
Time t;
t.setHour(h);
t.setMinute(m);
t.setAmPm(ampm);
Event e(desc, t);
this -> event[day] = &e;
}
Creates a new Event e on the stack. Then it saves a pointer to that local variable. As soon as your function returns, that pointer is no longer valid and using it will result in undefined behavior (such as a seg fault, but it could do many other things).
To fix it, work out whether those arrays should be arrays of pointers, or just arrays of objects. If you definitely want to use pointers, then you will need to work out how you control their life time. Alternatively, you could use a smart pointer that will look after the object's lifetime for you.
Note: this is just the first thing that jumped out at me, there may be other problems.