Thread: C++ handles uninitialized variables

Can you help me, explain question this, i dont understand it

How does C++ handles uninitialized variables?


thanks.

It doesn't (unless the variable is a non-POD, in which case the defaut constructor is invoked).

Space large enough for the particular data-type is allocated on the stack, but consequently the value of that stack space is left unchanged. It is not zero or some common arbitrary value, it is whatever was there to begin with.

Try the following and see what you get:

Code:

#include <iostream>

int main()
{
  int num;
  std::cout << num << "\n";
  return 0;
}

Your output will be some seemingly random numbers, and it will differ from what I get, or anyone else gets.

thanks you, but can you detail it more

Originally Posted by akaile

thanks you, but can you detail it more

How could one possibly elaborate on the statement "it doesn't"?

Nothing happens. No code is executed. Not a single bit is disturbed.

Clear enough now?

thanks all