※ 引述《pelicanper (派立肯)》之铭言： : There are huge differences between: : student.name (without information hiding) : student.getName() (with information hideing) : When outside codes want to change the name temporarily, for example, : in some situations you want to print out "王先生" instead of "王小明". : //case without information hiding : //what happens if you forget to change it back? : String tempName = student.name; : tempName = "王先生"; (student.name also changed) 这个例子不对，这里 student.name 并不会跟着改变！ : //case with information hiding : //student.name is safe : String tempName = student.getName(); : tempName = "王先生"; (student.name never changes) : A good programmer usually uses private, at least proteted, to secure : the value of variables. : When I studied JAVA programming in school, it would be zero mark : if I wrote codes without information hiding... 我的例子长这样： public class BadSchool { public List<String> studentNames; } public class GoodSchool { private List<String> studentNames; public List<String> getStudentNames () { return Lists.newArrayList(studentNames); // defensive copy } } 在 GoodSchool 里，因为外部经由 getter 拿到的其实是 copy，所以没有办 法直接改到内部的值，也就保护了内部的值不会被不预期地改变。使用 getter 的好处就是，你不见得要直接回传 member field，你可以同时做一些别的事， 让自己的 code 更有弹性。 -- Just because you deserve this doesn't mean they're gonna give it to you. Sometimes you gotta take what's yours. ── Kenny Ray Carter --

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