CODEWITHSUNDEEP
javainheritanceconstructorumlabstract-class
user8581108
user8581108

Reputation:

Abstract classes and Constructor issues and this UML diagram

So I have to build some classes using this UML diagram.

enter image description here

I'm have trouble with Circle and Square.

I understand that Circle inherits from Ellipse, who inherits from Shape. I understand that when you use a subtype's constructor, the first line in the body should be super().

What I don't understand is how I'm supposed to do this with my diagram. I don't know where double r is going and I don't know how I can call super(x,y) when there is no constructor in Ellipse or Shape that take just those two parameters. Same idea with square.

I get constructor errors when I follow the UML exactly.

Upvotes: 1

Views: 3093

Answers (1)

Oleg
Oleg

Reputation: 6314

Circle is an ellipse that has both focal points at the same location i.e it's defined by only one radius. So if your circle constructor is:

Circle(double x, double y, double r)

Your need to call the ellipse constructor with:

super(x, y, r, r)

The same with square and rectangle.

Upvotes: 2

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