java编程思想第4版中文版的几处谬误？

Answer 1

书翻译的不准确，没了！

Such an obvious problem, everyone knows it...

Do you have to have someone else confirm it for you before you can have the confidence to think that the problem is with the book and not yourself?

Answer 2

The original English text (page 169) is:

It's important that all of the methods in Cleanser are public.

As for the first question, the original text (page 168) is:

First, in the Cleanser append() method, Strings are concatenated to s using the += operator, which is one of the operators (along with '+') that the Java designers " overloaded" to work with Strings.

Answer 3

The translation is inappropriate and should be translated as "overloading"
If you know C++, you will know that this is equivalent to the String class reimplementing the "+=" operator. "+=" can be used for string splicing.