The keywords goto and const are C++ keywords reserved, but not currently used, in Java.  This enables Java compilers to identify them and to produce better error messages if they appear in Java programs.  The literal values true, false, and null are not keywords, just like literal value 100.  However, you cannot use them as identifiers, just as you cannot use 100 as an identifier; assert is a keyword added in JDK 1.4 and enum is a keyword added in JDK 1.5.