Java和Scala中C#的访问修饰符的等价物是什么？

以下是Java和Scala中与C#的访问修饰符最接近的等价物.在内部(在同一组件内可访问)的情况下,没有确切的等价物.在Java中,您可以限制对同一个包的可访问性,但是包更直接等同于C#的命名空间,而不是它们对于程序集.

(下表中的“无修饰符”被解释为应用于类成员.也就是说,在C#类中,没有修饰符的成员是私有的.顶级类型不是这样,默认为内部类型.)

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| C#                  | Java            | Scala                    | Meaning                                                                                                       |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| no modifier         | private (1)     | private                  | accessible only within the class where it is defined                                                          |
| private             |                 |                          |                                                                                                               |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| protected           |   --            | protected                | accessible within the class and within derived classes (2)                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| internal            | no modifier     | private[package_name]    | accessible within the same assembly (C#) or within the same package (Java / Scala) (3)                        |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| protected internal  | protected       | protected[package_name]  | accessible within derived classes (2) and anywhere in the same assembly (C#) or package (Java / Scala) (3)    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| public              | public          | no modifier              | accessible anywhere                                                                                           |
 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(1)在Java中,内部类的私有成员对外部类是可见的,但在C#或Scala中则不然.在Scala中,您可以说private [X]其中X是获取Java行为的外部类.

(2)在C#和Scala中,受保护的成员在类中是可见的,如果它是该类的实例或另一个派生类的成员,但如果它是较少派生类的实例的成员则不可见. (在Java中也是如此,除非由于它位于同一个包中而可以访问它.)

示例(在C#中)：

class Base
{
    protected void Foo() {}

    void Test()
    {
        Foo(); // legal
        this.Foo(); // legal

        new Base().Foo(); // legal
        new Derived().Foo(); // legal
        new MoreDerived().Foo(); // legal
    }
}

class Derived : Base
{
    void Test1()
    {
        Foo(); // legal
        this.Foo(); // legal

        new Base().Foo(); // illegal !
        new Derived().Foo(); // legal
        new MoreDerived().Foo(); // legal
    }
}

class MoreDerived : Derived
{
    void Test2()
    {
        Foo(); // legal
        this.Foo(); // legal

        new Base().Foo(); // illegal !
        new Derived().Foo(); // illegal !
        new MoreDerived().Foo(); // legal
    }
}

(3)在Scala中,您可以通过指定最内层的包来获取Java行为,但您也可以指定任何封闭包.