Well if you have mock exams, you can use those code snippets to verify the answer choices and eventually reinforce whatever concept that question is asking.
WARNING: using this approach isn't good because you tend to have memorized/recognized the question by the time you take the exam.
Another approach is simply to create some random programs/classes to
test say access modifiers. Changing the modifier from public to protected or package default, will the code compile? If compile success, will there be runtime exception (eg failed to call method)?
Say for exception handling, the rule is that the subclass must be caught before the parent class (eg catch FileNotFoundException then IOException). Changing the order will give you compile error. Verify it.
With
Java 7, multiple exceptions can be caught on a single line. Will the order make a difference? Can the exceptions list have a subclass and its parent class?
Depending on what topic you are studying, you can create many small programs to test each area. Imagination and creativity will help you think of programs to learn.
Good luck.
