Java polymorphism pros and cons and parent-child class transition conditions

Polymorphic Parent-Child class transition conditions:

The principle of forcing a parent class in Java to be cast to a subclass: the reference of the parent type to the instance of which child class, which can be converted to a reference to which subclass.

Benefits of Polymorphism:

You can accept arbitrary subclass objects as formal parameters.

Disadvantages of polymorphism:

You cannot use the unique properties and behaviors of subclasses.

Java polymorphism pros and cons and parent-child class transition conditions