How do I abstract a class? Why abstract classes? What is the role? What is polymorphic? How to achieve polymorphism?

How do I abstract a class? Why abstract classes? What is the role? What is polymorphic? How to achieve polymorphism?
In writing, we talk about how we understand these characteristics of object-oriented.

Reply to discussion (solution)

Since it's a discussion, let's talk about your opinion first.

Abstraction is the play of Imagination Gaga

What does PHP say about the polymorphic state?

What does PHP say about the polymorphic state?
...... No comment

What does PHP say about the polymorphic state?
I heard there was. Ha ha.

Describing your thoughts in words is not a return to writing?

In fact, you the problem itself is abstract class, all the replies are to achieve polymorphism

Upstairs is the solution Ah ~ ha haha

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