Java Learning · Primary knowledge object-oriented basic two

Package

1. Why you need to use the package

A) solve the problem of class names

b) easy to manage classes

1. How to use the package

A) The first non-annotative statement of a class

b) Name: The domain name is written backwards, plus the module name

1. Precautions

A) Do not use the default package

JDK Main Package

Import

1. Why you need to use the package

2.import How to use

3. Precautions

4. Static Import

Java Learning · Primary knowledge object-oriented basic two