In conversation with Campbell I had mentioned four areas I care about as part of Core Java that aren't on the OCJP, so I am paying a bit less attention to them while the exam is in scope for me.
1. BigDecimal/BigInteger which came up today in this forum and reminded me to write this post.
2. Regex, very important in real life, often the best way to do interview problems, not in scope for the OCJP except maybe in .split()
3. Reflection, I think very important in Real Life, almost out of scope for the OCJP (they do use class literals for multiply-applied annotations, but nothing else from Reflection).
4. LocalDate/LocalTime I occasionally still see Date on mock exams, but not in any way that we see or are tested on the nasty details, these were on the Java 8 certs, but not the 11. Still, don't leave home without 'em.
No action item here, they just came up as important stuff I am semi-ignoring in favor of stuff in scope for the exam, so I tend to be quiet about them...
RTFJD (the JavaDocs are your friends!) If you haven't read them in a long time, then RRTFJD (they might have changed!)
Yes, BigDecimal is an important part of basic Java®, as far as I am concerned. But how do you write multiple choice questions about it? You can't ask about operator precedence or anything like that. The most you can do is ask about methods:-
What is the output of the following code:-a: No output: throws an exception
e: No output: fails to compile
That sort of question will simply add noise to the exam and little value.
Weird. Once you start moving from apps run from the command line/terminal, you can use neither. In fact then System.console() will return null, and any attempt to use the console will cause an exception to be thrown.
Maybe it is because once people get more experienced they move away from the command line/terminal? No, it can't be, because they have other questions requiring a command line/terminal.