java class modifiers

There are four types of access modifiers in Java, private, default, protected, public, and their access rights are raised sequentially, and private can only be called by this class. The default, which defaults to not write, can be called by all classes under the same package, and protected can be called by all classes under the same package, or by subclasses unde

The meaning of the access modifier in Java, public, private, PROTECTE, default, is explained:The most restrictive modifier in the Public:java language, commonly referred to as "public". Classes, properties, and methods that are modified by it are notCan be accessed only across classes, and across packages (package).The narrowest modifier for access restrictions in the Private:java language is generally referred to as "private." The classes, attributes

* Declaration of the class [Modifier] Class Modifiers: optional, for specifying access rights, the available values are public,abstract and finnal. Class name: In general, the first letter is required to be capitalized. Extends parent class name: optional, which specifi

Compared to C + + in public,proctected, private three access control, Java more than the default access control.Four types of access control permissions in Java are described briefly as four sentences:1) Private only this class is visible (same as C + +)2) default to this package visible/in-package access (C + + not)3) Protected is visible to this package and all

The protected methods and properties defined in a class are the same as the default permission methods and properties. For example, a class of protected methods and properties outside the package is not accessible through the class instance (can you access the default permissions of a class outside of the package metho

Access modifiers are typically used to modify properties and methods in a class, to constrain access to properties and methods; Public//This class, the same package, sub-category, others can access; protected//This class, the same package, the subclass can access, other can not access; Private//Only this

The concept and function of packageConcept:----is physically a folder----Logically a collection of logically related classesRole:----Avoid class names----Controlling access rightsNaming conventions:-----First level refers to the type of the project, such as com,org,gov, etc.------The second level refers to the company name that the project develops or runs, such as: Chinasofti,icss,huawei, etc.-----The third level refers to the name of the project, su

//Math.sin (12.34); //Math.tan (12.34); //... //exponential function//Math.exp (12.34); //Math.log (12.34); //... //Rounding method, rounding up , rounding up and rounding downSystem.out.println (Math.rint (12.74));//Who are you close to?System.out.println (Math.floor (12.74));//take the smallest integerSystem.out.println (Math.ceil (12.34));//take maximum integerSystem.out.println (Math.Round (12.34));//serious rounding, returns a long integerSystem.out.println (Math.min (

all the methods in the abstract class are implemented, or it is still an abstract class.B, Interface (interface)1.Interface Definition: A collection of abstract methods and constant values (all methods are abstract methods). It is a special kind of abstract class (a Xxx.class file is generated and the compiler automaticallyInterface KeywordsBefore addingAbstract)。2.features：A, in the interfaceConstantsBy d

When developing internal projects or individual modules (Non-public modules), the use of the modifiers on access rights may not be very noticeable, but access modifiers are important in the writing of public code or the development of an SDK class. The following is an understanding of public,protected,default,private, providing a way to:1. If it involves the invo

　Access modifier permissions from high to low are public, protected, default, Private.First, according to "whether is the same package", "whether is sub-category" divided into 4 cases + 5 cases of this type　　　　Second, the sub-class in the same package and non-subclasses in the same package are merged into the same package Access modifiers This class