Buffer Overrun Question

[janp3]

Good day everyone,

Could anyone explain to me why a buffer overrun does not happen here?
The char word was defined to use only 4 characters but later on you can add it characters larger than that. Just adding it on "SIZE+X".

Thank you. Your help is appreciated.


#include<iostream>
#include<iomanip>

using namespace std;

int main ()
{
const int SIZE=5;
char word[SIZE];

cout<< "Enter a word larger than 4 characters to cause an Buffer Overrun:";

cin.getline(word,SIZE+3); //Avoids Buffer Overrun
cout<< "You entered " <<word <<endl;

return 0;
}

[Duthomhas]

You actually are having a buffer overrun -- only, your program doesn't do anything that it makes a difference for.

Remember, the word[] array is stored on the local stack. And, your compiler has a lot of leeway deciding how to use memory, so you might not even see a problem in a small contrived example.

The problem is that you do not know when careless buffer overruns will bite you based upon a whole bunch of compile and partitioning issues working from the way your compiler built it all the way to how your OS manages memory.

Hope this helps.

[janp3]

Thanks Duoas.

It helps. I understand your point.