问题描述
Java中使用 Collections.singletonList（）有什么用？我知道它返回一个包含一个元素的列表。为什么我想要一个单独的方法来做到这一点？不变性如何在这里发挥作用？
What is the use of Collections.singletonList() in Java? I understand that it returns a list with one element. Why would I want to have a separate method to do that? How does immutability play a role here?
此方法是否有任何特殊的有用用例，而不仅仅是一种方便的方法？
Are there any special useful use-cases for this method rather than just being a convenient method?
推荐答案
说：
你问：
为方便起见...为了节省您必须编写一系列语句：
As a convenience ... to save you having to write a sequence of statements to:
- 创建一个空列表对象
- 添加一个元素，
- 用不可变包装器包装它。
这是方法规范的一部分;见上文。
It is part of the specification of the method; see above.
显然，有些用例可以方便地使用 singletonList 方法。但我不知道你会如何（客观地）区分普通用例和特别有用用例...
Clearly, there are use-cases where it is convenient to use the singletonList method. But I don't know how you would (objectively) distinguish between an ordinary use-case and a "specially useful" one ...
这篇关于使用Java的Collections.singletonList（）？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！