C++退出代码3221225477

Question

I am trying to run a simple C++ program on pointers but the output I am getting is " [Finished in 5.55s with exit code 3221225477] ". The Norton Data Protector on my system is blocking the file execution (I guess) but I don't know why? I deactivated the Data Protector but nothing changed. Kindly someone please take a look at the my code and explain to me, what is going on here? Thank You

    #include <iostream>
    using namespace std;


    int main()
    {   
        int x;
        int * ptr ;
        *ptr = x ; 
        cout<<ptr;
    
    }

Answer 1

The problem is that the variable x is unitialized and you're using the value of an uninitialized variable which leads to undefined behavior. Same goes for variable ptr , it is also uninitialized and dereferencing it leads to undefined behavior.

*ptr = x ;//undefined behavior because first x is uninitialized and you're using x and second ptr is also unitialized and you're dereferencing ptr 

You should do:

int x = 0;
int *ptr = &x;//now ptr is a pointer pointing to variable x

For this very reason it is advised that:

always initialize built in types in local/block scope otherwise they have garbage value and using/accessing that garbage value can lead to undefined behavior

UB(short for undefined behavior) means anything can happen Including but not limited to access violation error . Check out What does access violation mean? .