Problem with classes and pointers

unitron6991 (2)
I am trying to do this project. The basic directions are to make a program with a class that has two private variables, one a dynamic array of strings and the other is a variable that determines the length of the array. I am supposed to have a member function to add entries and another to delete entries. I have gotten the code to compile and am debugging it. This is the debug version of the main:

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#include <iostream>
#include <string>
#include "namearray.h"
using namespace std;

int main()
{
	int size1;
	int option;
	string entry;

	cout << "Input array size: ";
	cin >> size1;

	namearray NameOf(size1);

	cout << NameOf.get_size() << endl;

	int j=0;
	for ( j = 0; j <= size1; j++);
	{
		cin >> entry;
		NameOf.set_name(entry,j);
	
	}
	NameOf.display_name();
	
	
	return 0;
}


This is the header:

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#ifndef NAMEARRAY_H
#define NAMEARRAY_H


#include <iostream>
#include <string>
using namespace std;

class namearray
{
public:
	
	//default constuctor, sets to size = 1
	namearray();
	
	//constructor to initialize to a userdefined value
	namearray(int startsize);
	
	namearray(const namearray &arraycopy);
	
	namearray addEntry(namearray array1, string entryToAdd);

	namearray deleteEntry(namearray array1, string entryToDelete);

	~namearray();

	int get_size();

	void set_size(int num);

	string get_name(int index);

	void set_name(string word, int index);

	void display_name();

	void operator =(namearray array1);

private:

	string* name;

	int size;
};

#endif


And this is the implementation file:

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#include <iostream>
#include <string>
#include "namearray.h"
using namespace std;


namearray::namearray()
{
	size = 1;
	name = new string[size];
}

namearray::namearray(int startsize)
{
	size = startsize;
	name = new string[size];
}

namearray::namearray(const namearray &arraycopy)
{
	size = get_size();
	name = new string[size];

	for ( int i = 0 ; i < size; i++)
	{
		name[i] = get_name(i);
	}
}

namearray namearray::addEntry(namearray array1, string entryToAdd)
{
	int newsize = array1.get_size() + 1;
	namearray Array2(newsize);

	for ( int i = 0; i < size; i++)
	{
		Array2.set_name(array1.get_name(i), i);
	}
	Array2.set_name(entryToAdd, newsize-1);

	delete[] array1.name;

	return ( Array2);
}

namearray namearray::deleteEntry(namearray array1, string entryToDelete)
{
	int entry_to_be_zorched = -9999;

	for ( int i = 0; i < size; i++)
	{
		if ( array1.get_name(i) == entryToDelete)
		{
			entry_to_be_zorched = i;
		}
	}
	if ( entry_to_be_zorched == -9999 )
	{
		return ( array1);
	}

	int newsize = array1.get_size() - 1;
	namearray Array2( newsize);

	for (int i = 0; i <= entry_to_be_zorched; i++)
	{
		Array2.set_name(array1.get_name(i), i);
	}
	for (int i = entry_to_be_zorched+1; i < size; i ++)
	{
		Array2.set_name(array1.get_name(i), i-1);
	}
	

	delete[] array1.name;

	return ( Array2);

}

void namearray::display_name()
{
	int i;
	cout << get_size()<<endl; //debug
	for ( i = 0; i < get_size(); i++);
	{
		cout << "blech" << endl;  //debug
		cout << i << ". " << get_name(i) << endl;
	}
}

string namearray::get_name(int index)
{
	string blech = name[index-1];

	return (blech);
}

void namearray::set_name(string word, int index)
{
	name[index-1] = word; 
}

int namearray::get_size()
{
	int blech = size; //debug
	return (blech);
}

void namearray::set_size(int num)
{
	size = num;
}

namearray::~namearray()
{
	delete[] name;
}

void namearray::operator =(namearray array1)
{
	int newsize = array1.get_size();
	if ( newsize > get_size())
	{
		name = new string[newsize];
	}
	for ( int i = 0; i < newsize; i++)
	{
		set_name(array1.get_name(i), i);
	}
}



And this is the output for array size 3, a,b,c:

I am able to input the array length and then...

It comes up with one of those funky Windows XP dialogs that says something like:

This program has encountered a problem and "needs to close".

What is going on???
jsmith (5804)
At first glance, I notice several problems.


1. Your default constructor creates an array of length 1. Why? Why not 0?

2. Your copy constructor calls get_name(i), which calls get_name on *this, not on
the object from which you are copying.

3. Why do addEntry and deleteEntry take namearrays as parameters and return a namearray?
You want to add or remove from *this, so there is no need for the extra parameter.

4. There are other problems with addEntry and deleteEntry, but I won't go into them until you
fix #3.

5. Your assignment operator leaks memory. In the expression a = b; where a and b are
namearrays, a may already contain names prior to the assignment. You need to ensure
that you free the memory used by a's internal array prior to "overwriting" it.

6. set_size() is a pointless method particularly in a public interface, unless you actually go and
create those elements. Think about what would happen if the array contained 5 elements,
then the user called set_size( 10 ). Where are indices 5-9 stored? You haven't even allocated
memory for them.
unitron6991 (2)
Thanks! Your suggestions really helped. My program runs fine now. I don't even know why I was doing that on those add and delete.
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