Based on below, am i right?
THanks for any help.
A global_A;
int global_int;
class A {
public : int x;
}
int main()
{
int local_int;
A local_A;
}
There are no references in your code, so any of your points that mention "references" make no sense.
In your example, both global object - global_int and global_A - are zero-initialized. Both local objects - local_int and local_A - contain indeterminate values, which means that local_int and local_A.x are not initialized.
P.S. Of course, as other already noted, your code is non-compilable. You can't declare A objects before declaring class A (and you are missing a ; after the class definition).
This code won't compile unless you forward declare A.
global_A reference is initialized to null - No, it will reference an A object. global_int is 0 - Think so, need to check. local_A reference is null - No, same as with global_A. local_int is uninitialized - Yes, it will get some garbage value. Both global_A.x and local_A.x is uninitialized - Yes.
You can always debug and see for yourself.
well guys .. i am more confused as i see responses from here. Anyway i did a test as shown below:
1 #include
2 using namespace std;
3
4 class A {
5
6 public :
7 A() : x(9) {};
8 int x;
9
10 };
11
12 A global_a;
13 int global_b;
14
15 int main() {
16
17 A local_a;
18 int local_b;
19 cout << "global_a.x = " << global_a.x << '\n';
20 cout << "local_a.x = " << local_a.x << '\n';
21
22 cout << "global_b = " << global_b << '\n';
23 cout << "local_b = " << local_b << '\n';
24
25 }
Results using my g++ compiler on ubuntu linux:
global_a.x = 9
local_a.x = 9
global_b = 0
local_b = 0
I do think local_b should be undefined but somehow compiler initialized it by default. However local_a .. i am not sure if that should be initialized by default. From the testing here .. local_a seem to be initialized. Not sure if that complies with standard c++ specification (eg C++ PRimer 4th edition says default constructor is used regardless where a class variable is declared - does that means variable of class type is initialized whether it is global or local?).
Whatever it is .. it is one big hell of confusion. Maybe i should quit learning C++. Java is so much more straight forward. Hell yeahhh!!