为什么StringBuffer / StringBuilder不会覆盖equals或hashCode？ [英] Why does StringBuffer/StringBuilder not override equals or hashCode?

问题描述

为什么StringBuffer / StringBuilder不会覆盖来自对象的 equals（）， hashcode（）方法？

Why does StringBuffer/StringBuilder does not override the equals(), hashcode() methods from object?

请建议我清楚的图片，以帮助理解问题...

Please suggest me clear picture that helps the understand the problem...

推荐答案

因为 StringBuffer 是可变的，其主要用途是构建字符串。如果你想比较内容，请调用 StringBuffer＃toString（）并比较返回的值。

Because StringBuffer is mutable, and its primary use is for constructing strings. If you want to compare content, call StringBuffer#toString() and compare the returned value.

它不是通常用于覆盖 hashCode（）的可变对象，因为修改了这个用作 HashMap中的键的对象可能导致存储的值丢失。

It is not generally useful to override hashCode() for mutable objects, since modifying such an object that is used as a key in a HashMap could cause the stored value to be "lost."

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