Core Java Interview Question Page 18

Question: Is &&= a valid Java operator?

Answer: No, it is not.

Question: Name the eight primitive Java types.

Answer: The eight primitive types are byte, char, short, int, long, float, double, and boolean.

Question: Which class should you use to obtain design information about an object?

Answer: The Class class is used to obtain information about an object's design.

Question: What is the relationship between clipping and repainting?

Answer: When a window is repainted by the AWT painting thread, it sets the clipping regions to the area of the window that requires repainting.

Question: Is "abc" a primitive value?

Answer: The String literal "abc" is not a primitive value. It is a String object.

Question: What is the relationship between an event-listener interface and an event-adapter class?

Answer: An event-listener interface defines the methods that must be implemented by an event handler for a particular kind of event. An event adapter provides a default implementation of an event-listener interface.

Question: What restrictions are placed on the values of each case of a switch statement?

Answer: During compilation, the values of each case of a switch statement must evaluate to a value that can be promoted to an int value.

Question: What modifiers may be used with an interface declaration?

Answer: An interface may be declared as public or abstract.

Question: Is a class a subclass of itself?

Answer: A class is a subclass of itself.

Question: What is the highest-level event class of the event-delegation model?

Answer: The java.util.EventObject class is the highest-level class in the event-delegation class hierarchy.

Question: What event results from the clicking of a button?

Answer: The ActionEvent event is generated as the result of the clicking of a button.

Question: How can a GUI component handle its own events?

Answer: A component can handle its own events by implementing the required event-listener interface and adding itself as its own event listener.

Question: What is the difference between a while statement and a dostatement?

Answer: A while statement checks at the beginning of a loop to see whether the next loop iteration should occur. A do statement checks at the end of a loop to see whether the next iteration of a loop should occur. The do statement will always execute the body of a loop at least once.

Question: How are the elements of a GridBagLayout organized?

Answer: The elements of a GridBagLayout are organized according to a grid. However, the elements are of different sizes and may occupy more than one row or column of the grid. In addition, the rows and columns may have different sizes.

Question: What advantage do Java's layout managers provide over traditional windowing systems? 0

Answer: Java uses layout managers to lay out components in a consistent manner across all windowing platforms. Since Java's layout managers aren't tied to absolute sizing and positioning, they are able to accomodate platform-specific differences among windowing systems.

Question: What is the Collection interface?

Answer: The Collection interface provides support for the implementation of a mathematical bag - an unordered collection of objects that may contain duplicates. 1

Question: What modifiers can be used with a local inner class?