本文主要是介绍《java in a nutshell》的一些学习笔记，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
1、java language does not use a local varible that has not been initialized.
java语言中，尚未初始化的局部变量不可以被使用(也就是说，在使用一个局部变量之前，必须先初始化它)。
2、There are some differences between class methods and instance methods.
类方法和实例方法之间是有区别的。
3、A class is a data type;a class value is called an Object.
“类”是一种数据类型；一个类的值称为对象。
4、Java only allows an object to be cloned if the object's class has explicitly declared itself to be cloneable by implementing the Cloneable interface.
Java中，只有当某个类通过实现Cloneable 接口显式的声明它自己是可克隆的，这个类的所属的对象才能被克隆。
5、"=="just test whether two references refer to the same object;it does not test whether two object have the same content.
“＝＝”只是判断两个“引用”引用的是否是同一个对象；它并没有判断两个对象的内容是否相同。
6、java is a "pass by value" language.However, when a reference type is involved ,the value that is passed is a reference.But this is not the same as pass-by-reference.
java语言是“值传递”的。只不过在涉及“引用”类型时，被传递的值是一个“引用”罢了。这与“引用传递”有所不同。
7、An array of primitve type cannot converted to any other array type,even if the primitive base types can be converted.
原语类型数据的数组不能转化为其他的数组类型，尽管这种原数据可以被转化。(比如，int型虽然可以转换为float型，但int[]型不能转化为float[]型。)
8、Java 5.0 introduces two new types of conversions known as boxing and unboxing conversions. Boxing conversions convert a primitive value to its corresponding wrapper object and unboxing conversions do the opposite.
java5引入了boxing 和unboxing 两种新的转化类型；boxing 可以将原语类型数据装化为它相应的类包装器对象，unboxing 则是反过来。
9、In Java 5.0 and later, you can import the static members of types as well as types themselves using the keywords 'import static'.
java 5.0以后的版本，通过“import”你不仅可以导入类，还可以导入这些类的静态成员，只需要使用'importstatic'关键字。
10、Each method that operates on a string typically returns a new String object that holds the modified string.
任何一种在字符串上操作的方法，返回的都是一个新的、包含修改过的字符串的String对象。
11、In java2 new io ,what implements nonblocking io is Selector!!!
在java2 新的io包(java.nio.*)中，真正实现了非阻塞的是Selector!!!
12、The New I/O API allows most channels (but not FileChannel) to be used in nonblocking mode and allows a single thread to manage all pending connections. This is done with a Selector object, which keeps track of a set of registered channels and can block until one or more of those channels is ready for I/O.
新的I/O API (java.nio.*)允许大部分的通道类(不包括FileChannel类)用于非阻塞模式，并且允许一个单独的线程来管理等待的连接。这是通过一个Selector 对象来实现的，它负责追踪已注册的通道对象，直到一个或多个通道已经准备好输入/输出才阻塞。
文章出自：http://blog.csdn.net/mildforest/article/details/1396571
这篇关于《java in a nutshell》的一些学习笔记的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！
