When is the finalize() called ? What is the purpose of finalization ?

Correct Answer: The purpose of garbage collection is to identify and discard those objects that are no longer needed by the application, in order for the resources to be reclaimed and reused

Correct Answer: The object need to be serialized when it?s sent over a network and when it?s state is saved Exceptions which occur during serialization are: a transient fields b when the base class is serialized then only base class fields are handled c static fields are ignored because they are not part of any state

Correct Answer: - The Dictionary class is an abstract class - Classes like Hashtable which map keys to values inherit from this class - An object can be looked for if a dictionary and a key is provided - Any non-null object can be used as a key and as a value

Correct Answer: For inserting, deleting, and locating elements in a Map, the HashMap offers the best alternative If, however, you need to traverse the keys in a sorted order, then TreeMap is your better alternative Depending upon the size of your collection, it may be faster to add elements to a HashMap, then convert the map to a TreeMap for sorted key traversal

Correct Answer: Constructors use this to refer to another constructor in the same class with a different parameter list Constructors use super to invoke the superclass's constructor If a constructor uses super, it must use it in the first line; otherwise, the compiler will complain

Correct Answer: An interface without having any methods and by implementing that interface if our objects will get same ability such type interfaces are called marker interface (or) ability interface (or) tag interface

Correct Answer: Complilation error

Explanation:

It is a compilation error it should be X extends Y implements Z

Correct Answer: None of the above

Explanation:

A is wrong because a class can extend nly one class .B is wrong because a class can implement any number of interfaces.C is wronb because both can can be done simulteneously.So, D is correct

Correct Answer: Package is a collection of related classes and interfaces package declaration should be first statement in a java class

Correct Answer: Type 4 (JDBC Net pure Java Driver) is the fastest JDBC driver Type 1 and Type 3 drivers will be slower than Type 2 drivers (the database calls are make at least three translations versus two), and Type 4 drivers are the fastest (only one translation)