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。
Programs store and operate on numbers in a locale-independent way. Before displaying or printing a number, a program must convert it to a String
that is in a locale-sensitive format. For example, in France the number 123456.78 should be formatted as 123 456,78, and in Germany it should appear as 123.456,78. In this section, you will learn how to make your programs independent of the locale conventions for decimal points, thousands-separators, and other formatting properties.
Using the factory methods provided by the NumberFormat
class, you can get locale-specific formats for numbers, currencies, and percentages.
With the DecimalFormat
class you specify a number's format with a String
pattern. The DecimalFormatSymbols
class allows you to modify formatting symbols such as decimal separators and minus signs.