Which classes are inherent in the Java language?

Question

For some reason I just thought of the question this past 2AM.
What classes are significant to the Java compiler? The list I thought of was:
Object -- implements wait() and synchronized
String -- all those convenience idioms we couldn't live without
StringBuilder -- for String operators like "a" + var
Integer, Long, Short, Char -- also for String operators like int i; String x = "abc" + i;
Throwable -- needed for catch clause
RuntimeException -- needed for implicit throw
How about the following? Does javac need to know about these? Or are they all handled by the runtime base classes?
Class
Constructor
Thread

Answer 1

AlanObject wrote:
jverd wrote:
ErrorI've never run into this class before, but wouldn't the JVM and not the compiler be dealing with this?> I don't think it has to know about StringBuilder or StringBuffer, as the JLS does not require their use for string concatenation with +. It's just that most implementations do it that way.Good point.
I don't doubt that in the creation of Java there were long discussions about this. They could have done away with the String-awareness of the language by forcing the use of direct methods but the usability issue won the day.
Also, are there now classes implied in the use of the for-each statement (Collection?) and in enums (Enumeration?)That would be Iterable, a shiny new abstraction. And, by extension, Iterator. Both them and enums, though, are tricks of the compiler, syntactic sugar. There's no new bytecode for those mechanisms (as yet)