java - 设置实例变量 public 并且不使用 setter 方法可能会破坏在 java 中使用我的类的协作者的代码？

Question

这个问题已经有答案了:

Why use getters and setters/accessors? (37 个回答)

已关闭 3 年前。

我在《Headfirst java》一书中找到了下面这段话。我不明白下面段落中的粗体部分。

Object: The point to setters (and getters, too) is that you can change your mind later, without breaking anybody else's code! Imagine if half the people in your com- pany used your class with public instance variables, and one day you suddenly realized, " Oops - there's something I didn't plan for with that value, I'm going to have to switch to a setter method." You break everyone's code. The cool thing about encapsulation is that you get to change your mind. And nobody gets hurt. The performance gains from using variables directly is so miniscule and would rarely be worth it.

Answer 1

该值的内部表示可能会发生变化，并需要使用新类型，可以使用 getter/setter 方法对其他代码隐藏该类型。