java中.this和.class的含义 [英] Meaning of .this and .class in java

问题描述

假设我们有一个班级名称Home。 Home.this 和 Home.class 之间有什么区别？他们指的是什么？

Let's say we have a class name Home. What is the difference between Home.this and Home.class? What do they refer to?

推荐答案

Home.this

Home.this 指的是 Home 类的当前实例。

Home.this refers to the current instance of the Home class.

此表达式的正式用语似乎是符合条件，如Java语言规范第15.8.4节所述。

The formal term for this expression appears to be the Qualified this, as referenced in Section 15.8.4 of the Java Language Specification.

在一个简单的类中，说 Home.this 和此将是等效的。此表达式仅用于存在内部类的情况，并且需要引用封闭类。

In a simple class, saying Home.this and this will be equivalent. This expression is only used in cases where there is an inner class, and one needs to refer to the enclosing class.

例如：

class Hello {
  class World {
    public void doSomething() {
      Hello.this.doAnotherThing();
      // Here, "this" alone would refer to the instance of
      // the World class, so one needs to specify that the
      // instance of the Hello class is what is being
      // referred to.
    }
  }

  public void doAnotherThing() {
  }
}

Home.class

Home.class 将 Home 类的表示形式java / lang / Class.htmlrel =noreferrer> Class object。

Home.class will return the representation of the Home class as a Class object.

这个表达式的正式术语是 class literal ，如Java语言规范的第15.8.2节所述。

The formal term for this expression is the class literal, as referenced in Section 15.8.2 of the Java Language Specification.

在大多数情况下，当使用反射，需要一种方法来引用类本身而不是类的实例。

In most cases, this expression is used when one is using reflection, and needs a way to refer to the class itself rather than an instance of the class.

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