What is Marker Interface?

Correct Answer: The finalize method is called by the garbage collector, just before releasing the object?s memory It is normally advised to release resources held by the object inside the finalize method

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: 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)

Correct Answer: use super keyword super keyword points immediate super class Class Sample { int a =23; } Class Sub extends Sample { String a = "bablu"; void show() { Systemoutprintln(a); //bablu System out println(thisa); //bablu System outprintln(supera); //23 } } Class Demo { Public static void main(string[] args) { sub s = new Sub(); sshow(); } }