Top-level and Inner Java Classes

	Top level nested class	Non static inner class	Local class	Anonymous class
Declaration Context	As static class member	As non-static class member	In block with non-static context	In block with non-static context
Accessibility Modifiers	All	All	None	None
Outer instance	No	Yes	Yes	Yes
Direct Access to enclosing context	Static members in enclosing context	All members in enclosing context	All members in enclosing context + local final variables	All members in enclosing context + local final variables
Defines static or non-static members	Both static and non-static	Only non-static	Only non-static	Only non-static
Constructors	Yes	Yes	Yes	No
Can use extends or implements clauses?	Yes	Yes	Yes	No

Functions Vs. Procedures

1. Function is mainly used in the case where it must return a value. Where as a procedure may or may not return a value or may return more than one value using the OUT parameter.

2. Function can be called from SQL where as procedure can not be called from the sql statements
3. Functions are normally used for computations where as procedures are normally used for executing business logic.

4. You can have DML (insert,update, delete) statements in a function. But, you cannot call such a function in SQL.

5. Function returns 1 value only. Procedure can return multiple values (max 1024).

6.Stored Procedure: supports deferred name resolution. Example while writing a procedure that uses table named tabl1 and tabl2 etc..but actually not exists in database is allowed only in during creation but runtime throws error Function wont support deferred name resolution.

7.Stored procedure returns always int by default zero. where as function return type could be scalar or table or table values

8. Stored procedure is precompiled execution plan where as functions are not.

9.A procedure may modify an object where a function can only return a value The RETURN statement immediately completes the execution of a subprogram and returns control to the caller.