You could test this by writing a class that has a single static variable
and just goes in an infinite loop, printing out the contents of that static
variable. Initialize the variable to some value "1", and run it.

   Then, edit the class so that now the value is initialized to "2" and run
it. Did the changes affect the first class?

   It probably depends on whether Eclipse runs programs in the same VM, or
creates a new VM for every program. Even if it's the same VM, might depend
on whether Eclipse fiddles with the ClassLoader (so that two instances of
the class object are loaded, each with their own member variable to
represent your static variable, or if only one instance is loaded).

   Since the answer is not immediately apparent (and since it may even
change in future optimizations of the Eclipse platform), you should probably
write your code in such a way so that it doesn't depend on any one specific
behaviour (i.e. don't use static members if it'll be a problem for you).

   - Oliver

No. Each run creates new JVM.