Reasons for a C++ Program Crash

C++ programs may crash unexpectedly for various reasons. Here are some typical causes of such crashes:

• Segmentation Fault

• A segmentation fault is a major cause of program crashes. It occurs when:
• Attempting to access a memory location that doesn’t exist.
• Trying to write to a read-only memory location.
• Accessing protected memory locations, such as kernel memory.
• Example:

int main()
{
    char *text;
    // Stored in the read-only part of the data segment
    text = "ABC";
    // Problem: trying to modify read-only memory
    *(text + 1) = 'n';
    return 0;
}

•  Stack Overflow
• Stack overflow happens due to non-terminating recursion, which exhausts the stack memory.
• Example:

#include <stdio.h>


void functionRecursive(int num) 
{
    if (num == 1)
        return;
    num = 6;
    functionRecursive(num);
}


int main() 
{
    int number = 5;
    functionRecursive(number);
}

• Buffer Overflow
• A buffer overflow occurs when a program writes data beyond the buffer’s boundary, overwriting adjacent memory locations.
• Example:

#include <bits/stdc++.h>
using namespace std;


int main() 
{
    char data[8] = "";
    unsigned short year = 1991;
    strcpy(data, "excessive");
    return 0;
}

• In this example, the string “excessive” is 9 characters long and encodes to 10 bytes including the null terminator, but the buffer can only hold 8 bytes. This overwrites the value of a year, causing unintended behavior.

• Memory Leak
• Memory leaks occur when a program allocates memory but fails to release it, gradually losing available memory.
• Example:

#include <stdio.h>
#include <stdlib.h>


int main() 
{
    for (int i = 0; i < 10000000; i++) 
    {
        // Allocating memory without freeing it
        int *memory = (int *)malloc(sizeof(int));
    }
}

• Exceptions
• Exceptions, such as divide by zero, can also cause program crashes.
• Example:

#include <bits/stdc++.h>
using namespace std;


int main() 
{
    int numerator = 10;
    int denominator = 0;
    cout << numerator / denominator;
    return 0;
}

If you have any questions or doubts, feel free to comment below or contact me directly. I’m here to help!