how to copy SubClass object in BaseClass copy constructor

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清歌不尽
清歌不尽 2021-01-28 10:53

I would like to make copy of SubClass object in BaseClass constructor. I need that the following code execute correctly.

class BaseClass{
    BaseClass() {}
             


        
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  •  长情又很酷
    2021-01-28 11:25

    It seems like you want the object of BaseClass to be an instance of SubClass which extends BaseClass.

    Is it even possible?

    -No. It is not possible.

    The instanceof operator returns true if the variable on left side satisfies IS-A condition of the variable or class on the left side.

    The SubClass IS-A BaseClass since it extends BaseClass. But the BaseClass can never be a SubClass, since it can't extend SubClass.

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