Definition objects and references for Java classes

The core idea of Java is the object of everything.

An object is an encapsulation of attributes (member variables, static properties) and methods (functions, dynamic properties)

Define a class

public class class Name {

Member variables

Method

}

Class Name Variable name = new class name ();

The variable name.

Object-oriented makes it easier to achieve a realm:

Reusable (reusability), Extensibility (Extensibility)

Component-oriented (Component)-a higher level of abstraction than an object

WebService

The difference between a member variable and a local variable

Member variables can be any of the data types in Java (underlying data types and reference types)

Member variables can be initialized or uninitialized (Java default initialization)

Member variables are scoped to the entire class

References to classes and objects

c C1 = new C ();

c C2 = new C (); ←C1, C2 here is the local variable

Definition objects and references for Java classes