Java Learning (11)

1. Packages (package) in Java

2.1 packages, corresponding to folders on disk

2.2 Create a new class that defaults to the default package

2.3 Declaring the Package keyword: packages

Package statement, pinned location

2.4 Importing a package keyword: import

Import package name. Class Name (* denotes all);

2.5 Effects:

Classify, resolve conflicting names

Classify and store, easy to find and manage

2.6 Naming conventions--reference materials

2 . Methods with Parameters

2.1 How to declare

Public return type method name (data type parameter name) {

.... Method body

}

2.2 Divided into 2 categories

2.2.1 No return type--void

2.2.2 has return type

Basic data types

Custom Classes-- return object of the class ;

Arrays-- return Array name ;

2.3 Types of parameters

Basic data Type (10-31)

Custom Classes--passing objects of a class

Array--only the "array name" needs to be passed

2.4 Calls

2.4.1 called in the current class--Method name (value list);

2.4.2 called in other classes--object name. Method Name (value list);

Iii. Summary of methods

Classification:

1, no return type, no parameters

2, no return type, parameters

3, there is a return type, no parameters

4. There are both return types and parameters

parameter or return type, which can be a common data type or a custom class or array

Java Learning (11)