Program Crashes While Setting Data in Array - c++

Question

I'm working on a project and every time I go to set example[4].m_dArray[3], the program crashes. I can set the value of every other variable up until I get to example[4].m_dArray[3]. Any help would be appreciated!
Prog1Class.h:
#include "Prog1Struct.h"
#pragma once
#include <iostream>
#include <string.h>
using namespace std;
class Prog1Class
{
private:
Prog1Struct example[4];
public:
Prog1Class();
~Prog1Class ();
void setStructData();
void getStructData();
void ptrFunction();
void refFunction();
void printStruct();
void printData();
};
Prog1Struct.h:
#pragma once
#include <string.h>
struct Prog1Struct {
int m_iVal;
double m_dArray[4];
char m_sLine[80];
};
Prog1Class.cpp:
#include "Prog1Class.h"
#include "Prog1Struct.h"
#include <iostream>
#include <string.h>
using namespace std;
Prog1Class::Prog1Class()
{
}
Prog1Class::~Prog1Class()
{
delete &example[4];
}
int main()
{
Prog1Class *aClass = new Prog1Class();
aClass->setStructData();
aClass->printData();
return 0;
}
void Prog1Class::setStructData()
{
for(int i=0;i<5;i++)
{
cout << "Enter an integer: ";
cin >> example[i].m_iVal;
for(int j=0;j<5;j++)
{
cout << endl << "Enter a double: ";
cin >> example[i].m_dArray[j];
}
cout << endl << "Enter a string: ";
cin.ignore(256,'\n');
cin.getline(example[i].m_sLine, 80, '\n');
cout << endl;
}
}
void Prog1Class::getStructData()
{
}
void Prog1Class::printData()
{
for(int i=0;i<5;i++)
{
cout << example[i].m_iVal;
for(int j=0;j<5;j++)
{
cout << example[i].m_dArray[j];
}
cout << example[i].m_sLine;
}
}

Answer 1

You need to change this
class Prog1Class
{
private:
Prog1Struct example[4];
to this
class Prog1Class
{
private:
Prog1Struct example[5];
In C++ arrays start at index 0, so an array of size 4 has valid indexes 0 upto 3. You're using example[4] so you need an array of (at least) size 5.
You also need to remove delete &example[4]; from your destructor as well.

Answer 2

First , delete &example[4]; should be delete [] example;
Second, where did you allocate memory for example?

Answer 3

You need to show the way the example object is declared? I'd suspect some mis-allocated or mis-declared problem with it. Your setStructureData doesn't do anything ostensibly wrong (assuming the array sizes match and the size of the string is fitting - it is a char array, not a pointer, correct?).

Answer 4

for (int i = 0; i < 5; i++)
// ^^^^^
Your for loops should have an ending condition with i < 4 since your arrays have only 4 spaces. Moreover, your delete should be delete[] example;.

Answer 5

Array deletion is delete [] example, not your way. Also, to use delete data needs to be allocated with new
Here is small example how to use new and delete
#include <iostream>
struct foo
{
foo() {std::cout <<"constructed\n";}
~foo() {std::cout <<"destroyed\n";}
};
int main ()
{
foo * pt;
pt = new foo[3];
delete[] pt;
return 0;
}
Also the output:
constructed
constructed
constructed
destroyed
destroyed
destroyed
I gave a lesson about new/delete and just now seen real problem:
example[4] is out of bounds. If you declare array with 4 elements it means you have indexes 0, 1, 2, 3 and nothing more.