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Vectors

G8rCre8or (16)
Hello, I am still struggling to declare my vectors. I know there is an error around line 185 and I just can't figure out how to solve it. Also, my professor is wanting me to use private functions instead of public. When I try to turn them private, more disaster strikes. Can anyone assist me please? I am just not grasping this. Thanks.

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#include<conio.h>
#include<iostream>
#include<cstdlib>
#include<vector>

using namespace std;

// Base class
class appointment
{
public:
	char*description;
// Declare structure date
	struct date
	{
		int y,m,d;
	};

// Create an object of the structure date
	date dt;
	int time;
public:
	appointment()
	{
	}
	appointment(int d, int m, int y)
	{
// three argument construct for setting the appointment date
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}

// declare a virtual function using three  variable of integers as an argument
	virtual char*occurs_on(int yr, int month, int day){};
};

// Class publicly derived from appointment
class OneTime:public appointment
{
public:
// Declares a default constructor to initialize the object of the class
	OneTime(){}
	OneTime(int d, int m, int y)
	{
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}
// defines the virtual function
	char*occurs_on(int yr, int month, int day)
	{

// check the condition if the day, month and yr is the same value of day
// month and year enter by user.
// Then stores the check value in the description.
		if(dt.d==day&&dt.m==month&&dt.y==yr)
		{
			description="one Time check up";
		}
		else
		{
			description="\0";
		}
// return the description
		return description;
	}
};

// Implements a class Daily for showing the daily appointments
// that's publically derived from the base class appointment

class Daily:public appointment
{
// declares a default constructor to initialize the value of class objects
	Daily(){}
// Declares a parameter constructor using three variables of integer arguments
	Daily(int d, int m, int y)
	{
// sets the appointment 
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}

// Define the virtual function for the derived class
	char*occurs_on(int yr, int month, int day)
	{
// check the condition if the day, month and yr is the same value of day
// month and year enter by user.
// Then stores the check value in the description.
		if(dt.d==day&&dt.m==month&&dt.y==yr)
		{
			description="daily appointment";
		}
		else
		{
			description="\0";
		}
// returns the value of the description
		return description;
	}
};

// Implements class Weekly for showing the weekly appointments
// Class is derived from base class appointment

class Weekly:public appointment
{
public:
// Declares the default constructor to initialize teh objects of the class
	Weekly(){}

// Declares parameters of constructo taking three variables of integers for arguments
	Weekly(int d, int m, int y)
	{
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}

// checks the type of appointment by comparing the date
	char*occurs_on(int yr, int month, int day)
	{
// declares a variable of integer data type
		int b;
// check the condition if the day, month and yr is the same value of day
// month and year enter by user.
// Then stores the check value in the description.
		if(dt.d==day&&dt.m==month&&dt.y==yr)
		{
			description="weekly appointment";
		}
		else
		{
			description="\0";
		}
		return description;
	}
};
 // Implement a class monthly for showing the monthly appointmnet which is 
// publically derived from the base class appointment

class Monthly:public appointment
{
public:

// Declares a default constructor to initialize the objects of the class
	Monthly(){}
	Monthly(int d, int m, int y)
	{
// constructor set the appointment date
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}
// checks the type of appointment
	char*occurs_on(int yr,int month,int day)
	{

// check the condition if the day, month and yr is the same value of day
// month and year enter by user.
// Then stores the check value in the description.
		if(dt.d==day&&dt.m==month&&dt.y==yr)
		{
			description="monthly appointment";
		}
		else
		{
			description="\0";
		}
		return description;
	}
};

// main function of the program
int main()
{

// declares four variable integer data types to display day, month and year
	int x;
	int dy,mn,ye;
	char*ar[4];

// vector of base class appointment
	vector<app> app(6);

// creates object of derived class OneTime and assigns the value
	app[0]=new OneTime(8,28,2013);
// creates object of derived class daily and show daily appointments and assigns value in it
	app[1]=new Daily(8,29,2013);
// creates object of the derived class weekly and shows appointments and assigns value in it
	app[2]=new Weekly(9,1,2013);
// creates object of derived class monthly and show monthly appointments and assigns value in it
	app[3]=new Monthly(p,2,2013);
// creates object of derived class OneTime and assigns the value in it
	app[4]=new OneTime(9,2,2013);
// creates an object of the derived class Monthly it show the monthly appointments and assigns value in it
	app[5]=new Monthly(9,2,2013);

// Enters the value of day, month and year from the user
	cout<<"enter day\t";
	cin>>dy;
	cout<<"enter month\t";
	cin>>mn;
	cout<<"enter year\t";
	cin>>ye;
	for(int i-0;i<6;i++)
	{
// calls the virtual function and stores values of day, month and year in the array
		ar[i]=app[i]->occurs_on(ye,mn,dy);
	}
// declares a variable of integer data type intialized at 0
	int i=0;
	while(i<4)
	{
		if(ar[i]!="\0")
		{
			cout<<"ar["<<i<<"]="<<ar[i];
		}
		i++;
	}
	getch();
	return 0;
}
S G H (2638)
We'd like to know what is the error.
But anyways that line of code may be translated to something like app app[6] and you cannot have an array named as its own type.

Maybe you meant vector<appointment*> app but you also need to clean up the pointers on your own.
Last edited on
Stewbond (2827)
Confirmed, the problem is that:
vector<app> app(6); should be vector<appointment*> app;
G8rCre8or (16)
Okay, so I made some of the adjustments and took out the b integer and the x integer cuz they really didn't do anything. Now I get the error; main.cpp(51): error C4716: 'appointment::occurs_on' : must return a value. This is the only error now showing. Below is the updated code. 
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#include<conio.h>
#include<iostream>
#include<cstdlib>
#include<vector>

using namespace std;

// Base class
class appointment
{
public:
	char*description;
// Declare structure date
	struct date
	{
		int y,m,d;
	};

// Create an object of the structure date
	date dt;
	int time;
public:
	appointment()
	{
	}
	appointment(int d, int m, int y)
	{
// three argument construct for setting the appointment date
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}

// declare a virtual function using three  variable of integers as an argument
	virtual char*occurs_on(int yr,int month,int day){};
};

// Class publicly derived from appointment
class OneTime:public appointment
{
public:OneTime(){}

// Declares a default constructor to initialize the object of the class
	OneTime(int d, int m, int y)
	{
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}
// defines the virtual function
	char*occurs_on(int yr, int month, int day)
	{

// check the condition if the day, month and yr is the same value of day
// month and year enter by user.
// Then stores the check value in the description.
		if(dt.d==day&&dt.m==month&&dt.y==yr)
		{
			description="one Time check up";
		}
		else
		{
			description="\0";
		}
// return the description
		return description;
	}
};

// Implements a class Daily for showing the daily appointments
// that's publically derived from the base class appointment

class Daily:public appointment
{
public:
// declares a default constructor to initialize the value of class objects
	Daily(){}
// Declares a parameter constructor using three variables of integer arguments
	Daily(int d, int m, int y)
	{
// sets the appointment 
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}

// Define the virtual function for the derived class
	char*occurs_on(int yr, int month, int day)
	{
// check the condition if the day, month and yr is the same value of day
// month and year enter by user.
// Then stores the check value in the description.
		if(dt.d==day&&dt.m==month&&dt.y==yr)
		{
			description="daily appointment";
		}
		else
		{
			description="\0";
		}
// returns the value of the description
		return description;
	}
};

// Implements class Weekly for showing the weekly appointments
// Class is derived from base class appointment

class Weekly:public appointment
{
public:
// Declares the default constructor to initialize teh objects of the class
	Weekly(){}

// Declares parameters of constructo taking three variables of integers for arguments
	Weekly(int d, int m, int y)
	{
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}

// checks the type of appointment by comparing the date
	char*occurs_on(int yr, int month, int day)
	{

// check the condition if the day, month and yr is the same value of day
// month and year enter by user.
// Then stores the check value in the description.
		if(dt.d==day&&dt.m==month&&dt.y==yr)
		{
			description="weekly appointment";
		}
		else
		{
			description="\0";
		}
		return description;
	}
};
 // Implement a class monthly for showing the monthly appointmnet which is 
// publically derived from the base class appointment

class Monthly:public appointment
{
public:	Monthly(){}

// Declares a default constructor to initialize the objects of the class

	Monthly(int d, int m, int y)
	{
// constructor set the appointment date
		dt.y=y;
		dt.m=m;
		dt.d=d;
	}
// checks the type of appointment
	char*occurs_on(int yr,int month,int day)
	{

// check the condition if the day, month and yr is the same value of day
// month and year enter by user.
// Then stores the check value in the description.
		if(dt.d==day&&dt.m==month&&dt.y==yr)
		{
			description="monthly appointment";
		}
		else
		{
			description="\0";
		}
		return description;
	}
};

// main function of the program
int main()
{

// declares four variable integer data types to display day, month and year

	int dy,mn,ye;
	char*ar[4];

// vector of base class appointment
	vector<appointment*> app(6);

// creates object of derived class OneTime and assigns the value
	app[0]=new OneTime(8,28,2013);
// creates object of derived class daily and show daily appointments and assigns value in it
	app[1]=new Daily(8,29,2013);
// creates object of the derived class weekly and shows appointments and assigns value in it
	app[2]=new Weekly(9,1,2013);
// creates object of derived class monthly and show monthly appointments and assigns value in it
	app[3]=new Monthly(9,2,2013);
// creates object of derived class OneTime and assigns the value in it
	app[4]=new OneTime(9,2,2013);
// creates an object of the derived class Monthly it show the monthly appointments and assigns value in it
	app[5]=new Monthly(9,2,2013);

// Enters the value of day, month and year from the user
	cout<<"enter day\t";
	cin>>dy;
	cout<<"enter month\t";
	cin>>mn;
	cout<<"enter year\t";
	cin>>ye;
	for(int i=0;i<6;i++)
	{
// calls the virtual function and stores values of day, month and year in the array
		ar[i]=app[i]->occurs_on(ye,mn,dy);
	}
// declares a variable of integer data type intialized at 0
	int i=0;
	while(i<4)
	{
		if(ar[i]!="\0")
		{
			cout<<"ar["<<i<<"]="<<ar[i];
		}
		i++;
	}
	_getch();
	return 0;
}
S G H (2638)
That's simple:

You're saying this function is able to return a char*:
virtual char*occurs_on(int yr,int month,int day){};
But you're not returning anything:
virtual char*occurs_on(int yr,int month,int day){};// <--- !!!

The workarounds are:

Making it "pure", requiring derived classes to redefine it:
virtual char*occurs_on(int yr,int month,int day) = 0;
Or returning 0:
virtual char*occurs_on(int yr,int month,int day){return 0;}

As I see you're using virtual classes, you may want to use a virtual destructor to avoid any kind of memory leaks:

 
 
virtual ~appointment() {} // somewhere inside the "class appointment{}" block


Also you're leaking memory from main:
After using std::vector<appointment*>, you should free its elements one by one:
this goes where _getch() is at (basically, after you finished to use app) 
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for(unsigned int i = 0; i < app.size(); ++i)
{
    delete app[i];
}
app.clear();
_getch();


...or use a smart pointer/unique pointer.
Last edited on
G8rCre8or (16)
Thanks, I made the suggested changes and am now getting an error message, Run-time Check Failure #2 - Stack around the variable 'ye' was corrupted. At this point I am absolutely clueless.
S G H (2638)
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if(ar[i]!="\0")
{
	cout<<"ar["<<i<<"]="<<ar[i];
}

You should change this to
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if(ar[i]!=0)
{
	cout<<"ar["<<i<<"]="<<ar[i];
}


Note, they are not the same.
The first one is of type char*, and is an actual address (It is NOT 0!).
The second one is of type int (converted to char*), and is not an address (This one IS 0!).
Basically you kept on reading/writing/accessing memory who wasn't initialized.

Also here:

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for(int i=0;i<6;i++)
{
	ar[i]=app[i]->occurs_on(ye,mn,dy);
}

will attempt to access ar[4] and ar[5], which you should not access as they are out of bounds.
You should resize ar to 6 elements, or use a std::vector<char*> with the same size of app.

EDIT:
For your learning purpose, the crash happened because you obviously accessed data you shouldn't have.
Last edited on
G8rCre8or (16)
Thanks EssGeEich. I appreciate the help.
S G H (2638)
Feel free to re-reply in case you need more help making things private (You shouldn't have big issues, but just in case...)
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