Thread: Need help with a class assignment

For Ex7, you called delete, but you never called new.

For a dynamic length array, you can use std::vector.
std::vector<mytype> myvec(my_size);

>>bool ShallowCompare (Phone*, Phone*);
Regarding this, however... don't do that.
Read more here: http://sourceforge.net/apps/mediawik...arameter_names

*shrug* It is the way to do it in C++ programs. But for experience, I guess, you may use new.

Mytype* p = new mytype[n]; // Where n is a variable whose size you want the array to be
// ...
delete [] p; // Do NOT forget to delete!

That also brings up smart pointers, which you class may or may not cover. You can find some information about them here to read up on later if case your class do not cover them:
SourceForge.net: Raw pointer issues - cpwiki
They are extremely important in C++ programming.

There are more problems in the code:
As pointed out already, there is a problem here:

Code:

	int exercise7Array[100];
	int* dataPtr = exercise7Array;
	// ...
	delete dataPtr;

Do not call delete on anything you did not get from new.

In Greatest, you have the same problem:

Code:

	int* temporaryPtr = array1;
	delete temporaryPtr;

Code:

if (*oldValue != NULL)

This is wrong, wrong, wrong. First off, never use NULL.
In proper code, all pointers will be initialized to nullptr (or better yet, a smart pointer is used). To test if a pointer is valid then, you check if it's not nullptr, or just if (p) where p is a pointer.
Comparing a dereferenced pointer (which does not point to another point) is wrong. You would realize this if you used nullptr instead of NULL (macros are evil).

So your logic there is wrong. You need to look at that and fix it.

Code:

	if (*oldValue == *newValue)
	{
		delete oldValue;
	}

Wrong, wrong, wrong! Do not delete what you did not new!
For that matter, deleting something does not set it to null. You must do that manually, like
OldValue = nullptr;

Code:

if (*oldValue != NULL)

Same problem as before.

Code:

system("Pause");

See SourceForge.net: Pause console - cpwiki

In regards to some of your evaluations, I have updated my code and it seems to be working fine.

Code:

// InClass Assignment 5
// 3/11/2011
//

#include <iostream>

#include <cstring>

#include <string>

#include <stdio.h>

#include <stdlib.h>

#include "Phone.h"

using namespace std;

bool ShallowCompare (Phone*, Phone*);

bool DeepCompare (Phone*, Phone*);

int Greatest (int*, int);

int GetGreatestInput();

int main()
{
	int static max;

	// PWU Exercise 1
	int someInt;
	
	int* intPointer;

	intPointer = &someInt;

	someInt = 451;

	if(someInt == 451)
		cout << "Passed PWU Exercise 1." << endl;
	else
		cout << "Failed PWU Exercise 1." << endl;

	someInt = 0;

	*intPointer = 451;

	if(someInt == 451)
		cout << "Passed PWU Exercise 1.\n" << endl;
	else
		cout << "Failed PWU Exercise 1.\n" << endl;

	// PWU Exercise 2
	char* charArrPointer;

	char initials[4];

	charArrPointer = initials;

	*charArrPointer = 'A';

	*(charArrPointer + 1) = 'E';

	*(charArrPointer + 2) = 'W';

	if (*charArrPointer == 'A')
		cout << "Passed PWU Exercise 2.\n" << endl;
	else
		cout << "Failed PWU Exercise 2.\n" << endl;

	// PWU Exercise 3
	Phone newPhone;

	Phone* structPointer = &newPhone;

	structPointer->country = 1;

	structPointer->area = 888;

	structPointer->number = 5551212;

	if ((structPointer->country == 1) && (structPointer->area == 888) && (structPointer-> number == 5551212))
	{
		cout << "Passed PWU Exercise 3.\n" << endl;
	}
	else
	{
		cout << "Failed PWU Exercise 3.\n" << endl;
	}

	// PWU Exercise 4
	Phone& structReference = newPhone;

	structReference.country = 1;

	structReference.area = 888;

	structReference.number = 5551212;

	if ((structReference.country == 1) && (structReference.area == 888) && (structReference.number == 5551212))
	{
		cout << "Passed PWU Exercise 4.\n" << endl;
	}
	else
	{
		cout << "Failed PWU Exercise 4.\n" << endl;
	}

	// PWU Exercise 5
	Phone* structPointer1 = &newPhone;

	Phone* structPointer2 = &newPhone;
	
	if (ShallowCompare(structPointer1,structPointer2))
	{
		cout << "Passed PWU Exercise 5.\n" << endl;
	}
	else
	{
		cout << "Failed PWU Exercise 5.\n" << endl;
	}

	// PWU Exercise 6
	Phone* structPointer3 = &newPhone;

	Phone* structPointer4 = &newPhone;

	if (DeepCompare(structPointer3, structPointer4))
	{
		cout << "Passed PWU Exercise 6.\n" << endl;
	}
	else
	{
		cout << "Failed PWU Exercise 6.\n" << endl;
	}

	// PWU Exercise 7
	
	int* dataPtr = new int[100];

	for (int count = 0; count < 100; count++)
	{
		*(dataPtr + count) = count;
	}

	for (int count = 0; count < 100; count++)
	{
		int temporary;

		temporary = *(dataPtr + count);

		if (count == 0)
		{
			temporary = max;
		}

		else
		{
			if (max < temporary)
			{
				max = temporary;
			}
		}
	}

	if (max == 99)
		cout << "Passed PWU Exercise 7.\n" << endl;
	else
		cout << "Failed PWU Exercise 7.\n" << endl;

	delete dataPtr;

	// PWU Exercise 8
	int* dataPtr2 = new int[100];

	for (int count = 0; count < 100; count++)
	{
		*(dataPtr2 + count) = count;
	}

	max = Greatest(dataPtr2, 100);

	if (max == 99)
		cout << "Passed PWU Exercise 8.\n" << endl;
	else
		cout << "Failed PWU Exercise 8.\n" << endl;

	// PWU Exercise 9
	int largestValue9 = GetGreatestInput();

	if (largestValue9 == 99)
		cout << "Passed PWU Exercise 9.\n" << endl;
	else
		cout << "Failed PWU Exercise 9.\n" << endl;

	// PWU Exercise 10


	// PWU Exercise 11
	int* oldValue = new int;

	int* newValue = new int;

	*oldValue = 40;

	if (*oldValue != NULL)
	{
		*newValue = *oldValue;
	}

	else
	{
		*newValue = 50;
	}

	if (*newValue == 40)
	{
		cout << "Passed PWU Exercise 11.\n" << endl;
	}

	else
	{
		cout << "Failed PWU Exercise 11.\n" << endl;
	}

	// PWU Exercise 12
	if (*oldValue == *newValue)
	{
		delete oldValue;
	}

	if (oldValue != nullptr)
	{
		cout << "Passed PWU Exercise 12.\n" << endl;
	}

	else
	{
		cout << "Failed PWU Exercise 12.\n" << endl;
	}

	// PWU Exercise 13


	// PWU Exercise 14


	// PWU Exercise 15


	// PWU Exercise 16


	// PWU Exercise 17


	// PWU Exercise 18


	// PWU Exercise 19


	// PWU Exercise 20


	system("Pause");

	return 0;
}

bool ShallowCompare (Phone* ptr1, Phone* ptr2)
{
	if(ptr1 == ptr2)
		return true;
	else
		return false;
}

bool DeepCompare (Phone* ptr1, Phone* ptr2)
{
	if ((ptr1->country == ptr2->country) && (ptr1->area == ptr2->area) && (ptr1->number == ptr2->number))
		return true;
	else
		return false;
}

int Greatest (int* temporaryPtr, int size)
{
	int maximum;

	for (int count = 0; count < size; count++)
	{
		int temporary;

		temporary = *(temporaryPtr + count);

		if (count == 0)
		{
			maximum = temporary;
		}

		else
		{
			if (maximum < temporary)
			{
				maximum = temporary;
			}
		}
	}

	delete temporaryPtr;

	return maximum;
}

int GetGreatestInput()
{
	int size;

	cout << "Input the number of values to be input: " << endl;

	cin >> size;

	cin.ignore(100, '\n');

	int* temporaryPtr = new int[size];

	for (int count = 0; count < size; count++)
	{
		int temporaryValue;

		cout << "Input an integer value to be put into the array: " << endl;

		cin >> temporaryValue;

		cin.ignore(100, '\n');

		*(temporaryPtr + count) = temporaryValue;
	}

	int largestValue = Greatest(temporaryPtr, size);

	return largestValue;
}

What did you change? Abovementioned problems still exist.

Maybe you should post the updated code then?

I still see a lot of erroneous deletes. And the prototypes have not been changed either.
All of which I pointed out earlier.

Crossposting is generally frowned upon.