The Java Tutorials have been written for JDK 8.Java教程是为JDK 8编写的。Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.本页中描述的示例和实践没有利用后续版本中引入的改进，并且可能使用不再可用的技术。See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.有关Java SE 9及其后续版本中更新的语言特性的摘要，请参阅Java语言更改。
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.有关所有JDK版本的新功能、增强功能以及已删除或不推荐的选项的信息，请参阅JDK发行说明。
With the knowledge you now have of the basics of the Java programming language, you can learn to write your own classes.有了Java编程语言的基础知识，您可以学习编写自己的类。In this lesson, you will find information about defining your own classes, including declaring member variables, methods, and constructors.在本课程中，您将找到有关定义自己的类的信息，包括声明成员变量、方法和构造函数。
You will learn to use your classes to create objects, and how to use the objects you create.您将学习使用类创建对象，以及如何使用您创建的对象。
This lesson also covers nesting classes within other classes, and enumerations本课程还将介绍在其他类中嵌套类以及枚举
dot operator to access the object's instance variables and methods.dot运算符访问对象的实例变量和方法。
dot operator that you learned about in the preceding section:dot运算符的类的更多方面，这些对象引用和点运算符是您在上一节中了解的：
this keyword, class vs. instance members, and access control.this关键字、类与实例成员以及访问控制返回值。