A good introduction, but chapter ordering seems bizarre - e.g. several on data structures injected between introduction and elaboration on class inheritance.
Also some bad practices seemingly needlessly introduced - throwing an int as a method of passing data for example.
Also much repetition - a single page will state something once, have a highlight box with the text copy and pasted, and then state it again before elaborating. Multiple pages of example then follow. It will be mentioned again in chapter summary.
If it's important, the highlight box is good. But it doesn't need to also appear in main body, except to elaborate; not to restate. No one reads "body but no highlights". Chapter summary is good and I only object to it as it feels like the 50th time I'm reading the same text in some cases.
Could easily be trimmed 25% without losing ease of reading. Readers can re-read, it doesn't need to be stated twice.
-- * It doesn't need to be stated twice. * --
It doesn't need to be stated twice, because readers can re-read.
In summary: format could be improved by minimising repetition.