Java有没有C#那样可以对某个类进行扩展，添加新的方法

Question

例如帮String类型扩展一个ToInt()方法

Answer 1

String class is special... Others can be inherited and then added methods

Answer 2

No. Java的类是死的, 一但写好就不再有更改能力. 你应该不是问, 通过继承来添加新的方法. 如果有的话, Scala也不用费劲搞个隐式视图To add methods to existing classes.

Well, this is not solid evidence either.

Answer 3

Are you talking about the interface?

Answer 4

No. Scala and PHP have trait.

Java doesn’t even have the ability to alias classes.

Answer 5

Decorator mode.