Dynamic array in classes c++ [SOVED] - c++

Question

I created a header file polygon.h and a polygon.cpp
polygon.h:
#pragma once
#include <iostream>
using namespace std;
class Polygon {
protected:
int numSides;
int* sides;
public:
Polygon(int nSides);
Polygon(const Polygon&);
~Polygon();
int getNumOfSides();
int perimeter(); // perimeter = hekef
bool operator==(Polygon);
};
polygon.cpp:
#include <iostream>
#include "Polygon.h"
using namespace std;
Polygon::Polygon(int nSides) {
this->numSides = nSides;
this->sides = new int[nSides];
if (nSides != 3 && nSides != 4)
{
cout << "Enter sides for polygon: " << endl;
for (int i = 0; i < nSides; i++)
cin >> this->sides[i];
}
};
Polygon::Polygon(const Polygon& other) {
this->numSides = other.numSides;
this->sides = new int[other.numSides];
for (int i = 0; i < this->numSides; i++)
this->sides[i] = other.sides[i];
};
Polygon::~Polygon() {
delete [] this->sides;
};
int Polygon::getNumOfSides() {
return this->numSides;
};
int Polygon::perimeter() {
int sum = 0;
for (int i = 0; i < this->numSides; i++)
sum += this->sides[i];
return sum;
};
bool Polygon::operator==(Polygon other) {
return (this->getNumOfSides() == other.getNumOfSides() && this->perimeter() == other.perimeter());
};
I'v created a Main file as well but it doesn't matter.
The problem is when I'm passing in for example into numSides the value 5 and the program should make from sides a new dynamic int array with 5 slots as for this example, but instead, while debugging it I find out that it creates only 1 slot as if it is just a regular integer and when I set in the 5 values into sides (as for this example with 5), sides ends up containing only the first value I have entered.
I will be happy if someone will help and even solve this problem :)

Answer 1

You didn’t say what debugger you are using, but for Visual Studio you can manually edit the debugger entry to be:
<pointer>, <size>
So in this case you’d say:
sides, 5
See this page for more info:
https://support.microsoft.com/en-us/help/198953/how-to-expand-an-array-pointer-in-the-visual-c-debugger-watch-window

Answer 2

As WhozCraig and 1201ProgramAlarm stated about std::vector in the comments above:
The debugger only knows that sides is a pointer, and doesn't know how many elements it points to. If you use std::vector you'd be able to see all of the points.
Stating the obvious, std::vector<int> sides; rather than manual memory management would make this trivial, and as a bonus, eliminates the need for a numSides member as well. That said, you're usage from the "calling" code is relevant. It should be included in your question. You're also missing a copy-assignment operator, therefore introducing a recipe for a rule of three violation. Things to work on.
The fact I didn't see all of the slots is because I'm used to c# and less working with pointers, and the int pointer was pointing on the start of the array.