Can you make a constructor final?

No, constructor can't be final.

What is static block?

• Is used to initialize the static data member.
• It is excuted before main method at the time of classloading.

Can we execute a program without main() method?

Ans) Yes, one of the way is static block.more details...

boolean contains(Object value)

boolean containsKey(Object key)

Enumeration elements( )

Object get(Object key)

Object put(Object key, Object value)

Object remove(Object key)

int size( )