Java Object-oriented course summary

1. What is an object? What is a class?

Relationship of classes and objects

Methods for defining classes

Method Five Elements

New keyword

Assignment of a reference type variable

Null and Nullexception

The difference between null and lowercase

2. Methods

Overloading and overriding

Construction method, with parameter construction

The This keyword, which can be overloaded

Array of reference types

3. Memory Management

Life cycle of member variables

Garbage collection mechanism

Stack, heap, method area

Method has only one copy

member variables and static variables

Upward styling

4. Inheritance (inheritance and polymorphism)

Overrides in inheritance

Overrides in the parent class

Parent class Keyword Super

Access Control (Package import)

Four types of permissions

Static final member variable method block

Final Modifier class

Static final constant

5. Abstract class Interface

Inheritance between interfaces and interfaces, which can inherit multiple

Interfaces can be implemented between

6, instanceof

Inner class (Halo-dependent)

Java Object-oriented course summary