Printing arrays using for loop in C++ - c++

Question

I'm trying to print the value of pointer array using for loop as usual, and I managed to print value stored in one object, but can't print the value stored in another object. My classes are defined in Predmet.h:
#include <iostream>
#include <string>
using namespace std;
class Predmet
{
public:
int numberOfItems;
string name;
Predmet();
~Predmet();
};
and Plaza.h:
class Plaza
{
public:
int length;
double x;
double y;
Plaza();
~Plaza();
};
My main.cpp looks like this:
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include "Plaza.h"
#include "Predmet.h"
using namespace std;
int main() {
int n, m;
int *numberOfBeaches;
Plaza *obj1;
Predmet *obj2;
cout << "Enter number of beaches (N): ";
cin >> n;
obj1 = new Plaza[n];
for (int i = 0; i < n; i++) {
cout << "Enter length and coordinates for " << i + 1 << ". beach: " << endl;
cin >> obj1[i].length;
cin >> obj1[i].x >> obj1[i].y;
}
cout << endl;
cout << "Enter number of items (M): ";
cin >> m;
obj2 = new Predmet[m];
numberOfBeaches = new int[n];
for (int i = 0; i < m; i++) {
cout << "Enter ordinal number of beach for " << i + 1 << ". item: ";
cin >> numberOfBeaches[i];
cout << "Enter how much of item you have and name of the item: ";
cin >> obj2[i].numberOfItems >> obj2[i].name;
}
int *p;
for (int i = 0; i < n; i++) {
p = find(numberOfBeaches, numberOfBeaches + n, i + 1);
if (*p == i + 1) {
for (int j = 0; j < m; j++) {
cout << i + 1 << ". " << obj1[i].x << " " << obj1[i].y << " D=" << obj1[i].length << " - predmeti: " << obj2[j].numberOfItems << " " << obj2[j].name << endl;
}
}
else {
cout << i + 1 << ". " << obj1[i].x << " " << obj1[i].y << " D=" << obj1[i].length << " - predmeti: " << endl;
}
}
delete[] obj1;
delete[] obj2;
delete[] numberOfBeaches;
system("pause");
return 0;
}
Everything was working until this point where I add printing for obj2[i].kolicina and obj2[i].opis, I get weird looking result as a print and this exception thrown, as you can see below:
What am I doing wrong? Thanks in advance.
EDIT:
After suggestions in the comments, I managed to fix the code (updated version above) to print it proper way, only when I have M > 1 (e.g. M = 2) I get duplicate printing of lines? How can I fix that?

Answer 1

The problem is with this line:
cout << i + 1 << ". " << obj1[i].x << " " << obj1[i].y << " D=" << obj1[i].duljina << " - predmeti: " << obj2[i].kolicina << " " << obj2[i].opis << endl;
obj2 is being defined as having m elements, yet you are using i, which has the values 0 <= i < n. I don't know what m's relation is to n, but that is certainly where you should start.

Answer 2

obj2contains melements:
obj2 = new Predmet[m];
brojPlaze contains n elements:
brojPlaze = new int[n];
you are looping over all Predmet in obj2:
for (int i = 0; i < m; i++) {
...
}
and inside the loop, you access element i of brojPlaze:
cin >> brojPlaze[i];
but i goes from 0 to m, and m can be greater than the n element brojPlaze contains. thus, you may access an element outside of the array, which can cause a lot of undesired effects...