#include <iostream>
using namespace std;
class Circle{
private:
float radius;
float xCoord;
float yCoord;
public:
Circle():radius(0),xCoord(0),yCoord(0){};
Circle(float r, float x, float y): radius(r), xCoord(x),yCoord(y){};
void PrintCircle(){
cout << radius << ' ' << xCoord << ' ' << yCoord;
}
};
class Cylinder{
private:
Circle circle;
float height;
public:
Cylinder():height(0){};
Cylinder(float r, float x, float y, float h):circle(r,x,y),height(h){};
void PrintCylinder(){
circle.PrintCircle();
cout << ' ' << height << endl;
}
};
int main(){
Cylinder c1;
c1.PrintCylinder();
Cylinder c2(5,5,5,5);
c2.PrintCylinder();
return 0;
}
Output:
0 0 0 0
5 5 5 5
In Cylinder class, I declared a Circle object member, which calls Circle's default constructor. Cylinder c1 verifies this. Then in Cylinder c2, I use the other Circle constructor on the Circle object.
My question - does the Circle object in c2 use two constructors? Why does this work? Or is this merely how object declarations within classes work?
EDIT: I'm not asking about about member initialization lists.
Say I wanted to create a Circle object in main() using its default constructor.
int main(){
Circle c;
}
Now look at the data members of Cylinder class.
class Cylinder{
private:
Circle circle; //Default constructor?
float height;
}
When creating a Cylinder object, would Circle circle call its default constructor automatically? If it does then that brings me to the 'two constructors' point.
For Cylinder c2, that would mean its Circle object calls its constructors Circle() then Circle(float r, float x, float y) due to Cylinder(float r, float x, float y, float h):circle(r,x,y),height(h){}.
