C++ Programming - Objects and Classes - Discussion

In above example, immediate to classes declarations, objects I and B are also constructed in global space so that I.B.Display() will give value any of its member initialized to default i.e here y is 0.

Note 1: By keeping declaration in global space and try to create objects I and B inside main() then I.B.Display() will give any of its member value as Garbage.

Note 1: Inside main(), declare class as static and then create objects also, in this case I.B.Display() will give value any of its member initialized to default i.e here y is 0.


#include <iostream>
using namespace std;

class Bix
{
int x;
float y;
public:
void Display()
{
cout<< y << endl;
}
}B;

int main()
{
static class Bbb
{
int x;
float y;
public:
void Display()
{
cout<< y << endl;
}
}Bb;

Bix B1;
B.Display();
B1.Display();
Bb.Display();
return 0;
}

It's all about logical assignments.

y = x = (x = 4*4);

// Successful assignment " x=4*4 " returns.
// value 1 to x, in turn successful assignment " x = (...) ".
// returns value 1 to y, so y = 1; next.

y = --y * y; // --y is operated 1st so y = 0 now, then 0*0 = 0.

No I am not agree with it @Ashwak.

Class member's default values is not zero. Static storage duration are zero-initialized at the program startup.

The void function was not called only display is invoked ? then how initialized y=x=(x=4*4).

How you say y=x=(x=4*4) is equal to 1?

In this example, we are not calling function Function(). So, value of y & x are not changed that's why it's displaying 0.

The void Function (void) will not be called simply.

If we have written I.B.Function then things would have been different.

It is because we have a global object.

For global objects, all members are initialised to zero.

Because y is global variable for function display and global variable value by default is zero.

Since argument type of function is void therefore it takes no arguments. Hence answer is zero.

Hello.

I'd like to assert that the main function is returning a 0,
hence, 0!.