This book has presented only a subset of the Java language. Here's what was left out. Most of what follows can be ignored in all but the most demanding or advanced applications.

other primitive types: byte, short, char, long, float.
switch statements, do-while statements break statements, continue statements, label statements.
bitwise operators, non-shortcutting boolean operators, the ternary operator, other shortcut operators (+=, -=, %= etc), remainder operator for doubles
transient modifier, volatile modifier.
Serialization.
top-level nested classes, static nested classes