Location of declaration

Question

#include <iostream>
using namespace std;
int main()
{
int a,b;
int x=a+b;
cin>>a>>b;
cout<<x;
return 0;
}
I tried to add 2 numbers but the result was 8 no matter what numbers I give it but when I put int x=a+b after input of a and b it works.
I believes that the compiler thinks x a+b before input nit after but why 8 ?
#include <iostream>
using namespace std;
int main()
{
int a,b;
cin>>a>>b;
int x=a+b;
cout<<x;
return 0;
}

Answer 1

If you use a variable before giving it a value it can be anything. If you change `int a,b;` to `int blah,a,b;` you will probably get a different number.
The variable `a` sits somewhere in your computer's memory and whatever was written in that location before your main function was executed will be the value of `a`.

Answer 2

Kind of but which value that is, is unknown.

Answer 3

in other words there is default value for a and b