Which of the following are valied?

Correct Answer: Complilation error

Explanation:

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

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: 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: 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(); } }

Correct Answer: When writing Nodejs applications, ending up with hundreds or even thousands of dependencies can easily happen For example, if you depend on Express, you depend on 27 other modules directly, and of course on those dependencies' as well, so manually checking all of them is not an option! The only option is to automate the update / security audit of your dependencies For that there are free and paid options: 1 npm outdated 2 Trace by RisingStack 3 NSP 4 GreenKeeper 5 Snyk

Correct Answer: When we create string with new() Operator, it?s created in heap and not added into string pool while String created using literal are created in String pool itself which exists in PermGen area of heap String s = new String("Test"); does not put the object in String pool , we need to call Stringintern() method which is used to put them into String pool explicitly its only when you create String object as String literal eg String s = "Test" Java automatically put that into String pool