Vince Botteman wrote:The explanation starts with the sentence "Line 6 returns the number 3 since indexes are zero based." The index of number 6 in the string is 2 and not 3.
You are correct! Should definitely be Line 6 returns the number 2 since indexes are zero based. The remainder of the explanation is spot-on: total has a value of 6 (2 + 4) and charAt(4) will throw a StringIndexOutOfBoundsException.
Agreed. I'm collecting a bunch of minor exam issues and reporting to the publisher in one go. (The one about the botched question I reported as soon as I knew about it.) In the meantime, it is listed in the errata with you as the finder. Thanks for pointing it out!