The super in Java

Super appears in subclasses that inherit from the parent class.
There are three ways of being present:
First Kind
super.xxx; (XXX is the variable name or object name)
The meaning of this method is to get a variable or method reference in the parent class whose name is XXX.
You can use this method to directly access variables or objects in the parent class, modify assignments, and so on.
The second Kind
Super.xxx ();(xxx for method name)
This method is meant to directly access and invoke methods in the parent class.
Third Kind
Super ();
This method means that the invocation of the parent class's initialization method is actually called the Public xxx () method in the parent class-----but not limited to the direct parent class, which can be traced up

When a subclass calls a constructor method, it first calls the constructor of the parent class, and then calls its own construction method.

Super () and this () call constructor method overload must be written in the first sentence, the other code is written behind it

The super in Java