什么是C ++ Pair< L，R>的等价物。在Java？ [英] What is the equivalent of the C++ Pair<L,R> in Java?

问题描述

Java中有没有 Pair< L，R> 这是否有充分的理由？这个C ++构造的等价物是什么？我宁愿避免重新实现自己。

Is there a good reason why there is no Pair<L,R> in Java? What would be the equivalent of this C++ construct? I would rather avoid reimplementing my own.

似乎 1.6 提供类似的东西（ AbstractMap.SimpleEntry< K ，V> ），但这看起来很复杂。

It seems that 1.6 is providing something similar (AbstractMap.SimpleEntry<K,V>), but this looks quite convoluted.

推荐答案

在 上的线程comp.lang.java.help ，Hunter Gratzner对Java中存在 Pair 结构提出了一些论点。主要的论点是类 Pair 没有传达关于两个值之间关系的任何语义（你怎么知道first和second是什么意思？） 。

In a thread on comp.lang.java.help, Hunter Gratzner gives some arguments against the presence of a Pair construct in Java. The main argument is that a class Pair doesn't convey any semantics about the relationship between the two values (how do you know what "first" and "second" mean ?).

更好的做法是为每个应用程序编写一个非常简单的类，如迈克建议的类， Pair class。 Map.Entry 是一个在其名称中带有其含义的货币对的示例。

A better practice is to write a very simple class, like the one Mike proposed, for each application you would have made of the Pair class. Map.Entry is an example of a pair that carry its meaning in its name.

总结一下，我认为最好有一个位置（x，y），一个类范围（开始，结束）和一个类条目（键，值）而不是一般的对（第一，第二）关于它应该做什么的任何事情。

To sum up, in my opinion it is better to have a class Position(x,y), a class Range(begin,end) and a class Entry(key,value) rather than a generic Pair(first,second) that doesn't tell me anything about what it's supposed to do.

这篇关于什么是C ++ Pair< L，R>的等价物。在Java？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IT屋！