Java实例变量可访问性 [英] Java Instance Variable Accessibility

问题描述

Java中以下变量的可访问性有何不同？

What is the difference in the accessibility of the following variables in Java?

public class Joe {
    public int a;
    protected int b;
    private int b;
    int c;
}

我最感兴趣的是最后一个人在做什么。

I'm most interested in what the last one is doing.

推荐答案

• public：对任何人都可读/写


• protected：read /可写为
  子类的实例，并且来自封闭包


• private：读/写任何实例类
  和内部或外部（封闭）实例


• int c：
  package-private，可读/写
  同一个包内的所有类


• public: read/writable for anyone
• protected: read/writable for instances of subclasses and from within the enclosing package
• private: read/writable for any instance of the class and inner or outer (enclosing) instance
• int c : package-private, read/writable for all classes inside same package

请参阅 JLS 了解更多详情

编辑：添加了对受保护的评论，说明访问是从在同一个包里，你们是完全正确的。还添加了私人评论。我现在记得......; - ）

Added the comment for protected stating that access is granted from inside same package, you guys are totally right. Also added comment for private. I remember now... ;-)

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