Data Management Error C++ - c++

Question

I am having difficulties with my code. The issue is that even though my program runs all the way through, it still crashes at the end. My IDE gives me no disapproval and there is no indicator as to why my program is failing right at the end, so I am led to believe there is something going out of bounds or something messing up my stack. I have looked through my code and nothing appears to be out of bounds, so I am entirely confused on this matter.
I am using a header file I created, a file to contain my functions from the header file, and a main method file. The error is a result of the file containing my functions.
The fields of my class are
size - int
low - int
high - int
windowSize - int
*filteredArray - int
array[] - int
Here is the header file:
#ifndef FILTER_HPP_
#define FILTER_HPP_
#include<iostream>
class Filter {
int size;
int high;
int low;
int windowSize;
int *filteredArray;
int array[];
public:
// Constructor
Filter(int windowSize);
// Methods
void randArrayGen();
int* randArrayGenRecurHelper(int arrayRecur[], int count);
void randArrayGenRecur();
void printArrays();
int hanning(int ar[]);
void hanningFilter();
void graphicArrays();
int getSize();
int getHigh();
int getLow();
};
#endif /* FILTER_HPP_ */
Here is the code:
#include "Filter.hpp"
#include <iostream>
#include <time.h>
#include <stdlib.h>
#include <cmath>
#include <array>
#include <string>
#include <cstring>
using namespace std;
// Constructor
Filter::Filter(int num){
size = ((rand() % 25) + 25);
high = ((rand() % 6) + 5);
low = ((rand() % 6) + 5) * -1;
windowSize = num;
randArrayGen();
hanningFilter();
}
void Filter::randArrayGen(){
for(int i = 0; i < size;i++){
array[i] = (rand() % (high + low * -1)) + low;
}
}
int Filter::hanning(int ar[]){
int weightAvg;
if(windowSize == 3){
weightAvg = (ar[0] + ar[1] * 2 +ar[2]) / 4;
}
else if(windowSize == 5){
weightAvg = (ar[0] + ar[1] * 2 + ar[2] * 3 + ar[3] * 2 + ar[4]) / 9;
}
else if(windowSize == 7){
weightAvg = (ar[0] + ar[1] * 2 + ar[2] * 3 + ar[3] * 4 + ar[4] *3 + ar[5] * 2 + ar[6]) / 16;
}
else if(windowSize == 9){
weightAvg = (ar[0] + ar[1] * 2 +ar[2] * 3 + ar[3] * 4 + ar[4] * 5 + ar[5] * 4 + ar[6] * 3 + ar[7] * 2 + ar[8]) / 25;
}
else{
weightAvg = 0;
}
return weightAvg;
}
void Filter::hanningFilter(){
filteredArray = new int[size];
for(int i = 0; i < size; i++){
if(i - (windowSize/2) < 0 or i + (windowSize/2) > size - 1){
filteredArray[i] = 0;
}
else{
filteredArray[i] = hanning(&array[i-(windowSize/2)]);
}
}
}
int Filter::getHigh(){
return high;
}
int Filter::getLow(){
return low;
}
int Filter::getSize(){
return size;
}

Answer 1

You don't allocate memory for your array:
int array[];
And when you index it like:
for(int i = 0; i < size;i++){
array[i] = (rand() % (high + low * -1)) + low;
}
you invoke Undefined Behavior, since you go out of bounds (you request the first element for example, but from an array of unknown size).
You could declare the array with a fixed size, like this for example:
int array[100];
However, since this is C++, consider using std::vector. An immediate advantage is that you don't have to hardcode a size for your statically allocated array, but you can rely on the vector's ability to resize as the data are inserted/pushed into it.