Errata for OCP: Oracle Certified Professional Java SE 8 Programmer II Study Guide - page 160-161

[Anton Shaikin]

Sorry, if it was reported before, but I couldn't find.

p. 160:

"HashMap - Uses hashcode() to find keys"

should be hashCode.


p. 161:

Collection has a few methods that take lambdas, including removeIf(), forEach(), and merge().

Collection doesn't have merge() method, Map does.

[Jeanne Boyarsky]

Anton,
Thanks for reporting. You are the first to notice both and I've added them to the errata. For the later, it looks like we originally had Collections and the editor "fixed" it. The idea was to summarize by mentioning each method rather than specifying its location.

[Anton Shaikin]

Hi Jeanne,

Regarding your comment on the errata:

Chapter 3 In the second paragraph, “Collection has a few methods” should be “Collections has a few methods.” The idea was to include all the Collections types (Map has merge).

The part in bold should be "Collections have a few methods", if you mean Collections in general. Also, to avoid confusion with the Collections class, wouldn't it be better to say "Collections classes have a few methods" or "Java Collections Framework has a few methods"?

[Jeanne Boyarsky]

The Collections class *has* a few methods .

[Anton Shaikin]

Jeanne Boyarsky wrote:The Collections class *has* a few methods .

But if you meant Collections, the class, then the whole sentence wouldn't make sense: "Collections has a few methods that take lambdas, including removeIf(), forEach(), and merge().", because these methods are part of Collection, and Map classes.

[Jeanne Boyarsky]

You're right, I didn't. I thought I was in a different conversation and didn't check the context. I meant the collections framework. Fixed the errata.