31. Name three Component subclasses that support painting.
The Canvas, Frame, Panel, and Applet classes support painting.
32. What value does readLine() return when it has reached the end of a file?
The readLine() method returns null when it has reached the end of a file.
33. What is the immediate superclass of the Dialog class?
Window.
34. What is clipping?
Clipping is the process of confining paint operations to a limited area or shape.
35. What is a native method?
A native method is a method that is implemented in a language other than Java.
36. Can a for statement loop indefinitely?
Yes, a for statement can loop indefinitely. For example, consider the following:
for(;;) ;
37. What are order of precedence and associativity, and how are they used?
Order of precedence determines the order in which operators are evaluated in expressions.
Associatity determines whether an expression is evaluated left-to-right or right-to-left.
38. When a thread blocks on I/O, what state does it enter?
A thread enters the waiting state when it blocks on I/O.
39. To what value is a variable of the String type automatically initialized?
The default value of an String type is null.
40. What is the catch or declare rule for method declarations?
If a checked exception may be thrown within the body of a method, the method must either catch the exception or declare it in its throws clause.
Advanced Java Questions and Answer for Interview