Errata OCP Guide - Chapter 3

[Aurelien Gamet]

Hello,

In Chapter 3 page 115 the sentence near the bottom of the page:

A compiler warning is different from a compiler error in that all of the code still compiles with a compiler error.

should be:

A compiler warning is different from a compiler error in that all of the code still compiles with a compiler warning.

[Jeanne Boyarsky]

Good catch. Thanks for reporting it. I've added this to the errata

[Aurelien Gamet]

In chapter 3 page 131 at the top of the page, the second sentence after Java code reads:

Line 8 requests the element at index 2.

When it should be:

Line 8 requests the element at index 0.

[Jeanne Boyarsky]

Confirmed

[Aurelien Gamet]

I'm not as sure on this one but I think this is an errata. Sorry if I'm wrong.
Page 225 chapter 4, on the essential chapter called Write code for common intermediate operations.
It's written:

The flatmap() method flattens nested lists into a single level and removes empty lists.

I think it should be:

The flatmap() method flattens nested streams into a single level and removes empty streams.

As the signature for flatmap is:

flatMap(Function<? super T, ? extends Stream<? extends R>> mapper)

So the Function parameter of flatmap needs to return a stream, not a list.

[Jeanne Boyarsky]

Noted and logged. It wasn't a typo, but it is sloppy language. I mentally think of streams as lists sometimes when I shouldn't.