Answer the following statements true (T) or false (F)

Question

1. 6. It is legal to call a constructor as a member function of an object of a class, as in
```
class A
{
public:
A(){}
A(int x, int y):xx(x), yy(y) {}
// other members
private:
int xx;
int yy;
};
int main()
{
A w;
w.A(2,3); // Is this legal?
}
```
2. A constructor can be called implicitly or explicitly. (Implicitly means the compiler did it for you.) In the interest of uniformity in answers, please use class A; for your examples.
3. A class may not have another class type object as a member.
4. Any use of the keyword const is a promise to the compiler, and a request to the compiler to enforce the promise. What promises?

Answer 1

1. False.
You cannot call a constructor as if it were a member function. This writer’s compilers all give an error message that says the equivalent of this remark. The author of this code probably wanted w = A(2,3); which is legal, and does what this fragment appears to do.
2. True
A constructor can be implicitly called with the declaration A x;. The default constructor is called explicitly with syntax is A x = A();
If the declaration is A x(2), the constructor is called implicilty. The equvalent explicit constructor call is A x = A(2); and so on.
3. False
A class type may be treated exactly like any other type. An int can be a member of a class, so can another class be a type of a member of another class.
4. True.
We have seen several uses of const. A const call-by-reference parameter promises not to write code that could change the parameter, hence not to write code that could change the argument.. A const identifier definition promises not to write code that could change the identifier. Finally, a const member function.promises not to write code in the member function that could change the state of the calling object.