How can a class extend two classes in Java? -

If Java can only extend one square, and every square java.lang.Object Increases, so how can it expand another class? And how is the object not expanded in each class

If java can expand only one square, and every class increases java.lang.Object, then how can this increase another class?

When you say that extends AB, it means that the extension of A increases B and B object one class can get from one another Which can be obtained from the other and java.lang.Object at the top of the series. Java does not support multiple legacy, but supports multi-level legacy.

How does the "item expanded" not written in each category?

All sections are expanded in the code by the object , so this would be redundant coding.