CODEWITHSUNDEEP
javaoopobjectinheritance
user2540748
user2540748

Reputation:

Inheritance in Java, accessing child methods and using an array of parent class

I have a java program consisting of a class called Piece, has four children objects. Ie, Geometry, circle extends geometry, circle2 extends circle, etc.

I want to create an array of Geometry objects and access circle, or circle2 methods.

ex. Geometry[i].method1();

However, I cannot seem to do this. Is there a best practice for making an array of objects that have the same parent, and accessing methods of its child in this manner?

Upvotes: 1

Views: 4185

Answers (1)

gkrls
gkrls

Reputation: 2664

You can't call sub-class methods on parent-class objects. Think of it this way. A circle is a geometric shape. But not all geometric shapes are circles. So not all geometric shapes can have circle properties (and in this case methods).

What you have to do is tell the compiler to treat the Geometry object as a circle or any other sub-class Object under the parent-class Geometry. This is called "casting".

So basically you cast the Geometry object to a Circle object like this:

((Circle) Geometry[i]).method1();

Upvotes: 3

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