C++ Array Declaration Stack Overflow Exception

Error: Stack overflow when declaring a huge array in C++.

Unhandled exception at 0x00007FF60B7040C8 in Tutorial.exe: 0xC00000FD: Stack overflow (parameters: 0x0000000000000001, 0x00000081A80D3000). occurred


Problem code:

#include <iostream>
#include <fstream>

int main()
{
    //do something..

    int nar[10000000];

    //do something more..

    return 0;
}



Solution:

#include <iostream>
#include <fstream>

int nar[10000000];

int main()
{
    //do something..

    //do something more..

    return 0;
}


Explanation:

- Since it is declared global it is accessible globally.
- You do not have to explicitly delete this memory.
- This will put the array on heap and stack overflow will not occur.


References:

• https://stackoverflow.com/a/3138412
• https://stackoverflow.com/a/6159973 

This crash happens when a very large array is declared as a local variable. Locals live on the stack, which is small, so a big array there exhausts the stack and the program faults.

The fix is to allocate large buffers on the heap instead, for example with std::vector or new, which draw from the much larger heap. This is a common pitfall once sizes grow beyond a few thousand elements.