Question: Can a private method of a superclass be declared within a subclass?
Answer: Sure. A private field or method or inner class belongs to its declared class and hides from its subclasses. There is no way for private stuff to have a runtime overloading or overriding (polymorphism) features.
   

Question: Why Java does not support multiple inheritence ? 
Answer: Java DOES support multiple inheritance via interface implementation.
   

Question:What is the difference between final, finally and finalize?
Answer: o final - declare constant
               o finally - handles exception
               o finalize - helps in garbage collection
   

Question: Where and how can you use a private constructor.
Answer: Private constructor can be used if you do not want any other class to instanstiate the object , the instantiation is done from a static public method, this method is used when dealing with the factory method pattern when the designer wants only one controller (fatory method ) to create the object.
   

Question: In System.out.println(),what is System,out and println,pls explain? 
Answer: System is a predefined final class,out is a PrintStream object and println is a built-in overloaded method in the out object.
   

Question: What is meant by "Abstract Interface"? 
Answer: First, an interface is abstract. That means you cannot have any implementation in an interface. All the methods declared in an interface are abstract methods or signatures of the methods.
    

Question: Can you make an instance of an abstract class? For example - java.util. Calendar is an abstract class with a method getInstance() which returns an instance of the Calendar class. 
Answer: No! You cannot make an instance of an abstract class. An abstract class has to be sub-classed. If you have an abstract class and you want to use a method which has been implemented, you may need to subclass that abstract class, instantiate your subclass and then call that method.
   

Question: What is the output of x<y? a:b = p*q when x=1,y=2,p=3,q=4?
Answer: When this kind of question has been asked, find the problems you think is necessary to ask before you give an answer. Ask if variables a and b have been declared or initialized. If the answer is yes. You can say that the syntax is wrong. If the statement is rewritten as: x<y? a:(b=p*q); the return value would be variable a because the x is 1 and less than y = 2; the x < y statement return true and variable a is returned.

Question: What is the difference between Swing and AWT components?
Answer: AWT components are heavy-weight, whereas Swing components are lightweight. Heavy weight components depend on the local windowing toolkit. For example, java.awt.Button is a heavy weight component, when it is running on the Java platform for Unix platform, it maps to a real Motif button.

Question: Why Java does not support pointers?
Answer: Because pointers are unsafe. Java uses reference types to hide pointers and programmers feel easier to deal with reference types without pointers. This is why Java and C# shine.

Question: Parsers? DOM vs SAX parser
Answer: parsers are fundamental xml components, a bridge between XML documents and applications that process that XML. The parser is responsible for handling xml syntax, checking the contents of the document against constraints established in a DTD or Schema.

Question: What is a platform?
Answer: A platform is the hardware or software environment in which a program runs. Most platforms can be described as a combination of the operating system and hardware, like Windows 2000/XP, Linux, Solaris, and MacOS.

Question: What is the main difference between Java platform and other platforms?
Answer: The Java platform differs from most other platforms in that it's a software-only platform that runs on top of other hardware-based platforms. The Java platform has two components:

1. The Java Virtual Machine (Java VM)

2. The Java Application Programming Interface (Java API)

Question: What is the Java Virtual Machine?
Answer: The Java Virtual Machine is a software that can be ported onto various hardware-based platforms.