Question 1

What is a package?

Accepted Answer

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

Question 2

What is the fastest type of JDBC driver ?

Accepted 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)

Question 3

If sub class data member is hiding super class data member then how to access super class data member inside sub class methods?

Accepted 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(); } }

Question 4

How can you make sure your dependencies are safe ?

Accepted 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option is to automate the update / security audit of your dependencies For that there are free and paid options: 1 npm outdated 2 Trace by RisingStack 3 NSP 4 GreenKeeper 5 Snyk

Question 5

What is the difference between creating String as new() and literal ?

Accepted 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

Question 6

How do you handle error condition while writing stored procedure or accessing stored procedure from java ?

Accepted Answer

Stored procedure should return error code if some operation fails but if stored procedure itself fail than catching SQLException is only choice

Question 7

Which is a reserved word in the java programming language?

Accepted Answer

Reserved words are words that cannot be used as object or variable names in a Java program because they're already used by the syntax of the Java programming language. Java reserved words are keywords that are reserved by Java functions or other uses that cannot be used as identifiers (e.g., variable names, function names, class names). If a reserved word was used as a variable you would get an error or unexpected result. Examples : Int, Long, Abstract, Class, Break, Catch, Case, Public, Static, Void,...

Question 8

Which of the following best describes JavaScript?

Accepted Answer

JavaScript, often abbreviated as JS, is a high-level, interpreted programming language that conforms to the ECMAScript specification. JavaScript has * curly-bracket syntax, * dynamic typing, * prototype-based object-orientation, and * first-class functions. Uses : It is well-known as the scripting language for Web pages, many non-browser environments also use it, such as Node.js, Apache CouchDB and Adobe Acrobat.

Question 9

Is it possible to nest functions in javascript?

Accepted Answer

Yes, it is possible to nest functions in javascript

Question 10

Warning implicit declaration of function?

Accepted Answer

Function: A Function is a block of statement which perform some operation Declaring the function before using the function in program is known as implicit declaration of the function For Example:: int bar(void); // function (forward) declaration int main(void) { bar(); // bar was declared, the compiler has all the info return foo(123); // foo not yet known; impl decl warning } // not previously declared function definition int foo(int a) { return a; } // previously declared function definition int bar() { return 321; }

Question 11

How many constructors can a class have?

Accepted Answer

A class can have any number of constructors. If a class have more than one constructor, we call it as the constructor is overloaded.

Question 12

What compilers apple using ?

Accepted Answer

The Apple compilers are based on the compilers of the GNU Compiler Collection

Question 13

What are the different layers of cloud computing?

Accepted Answer

Cloud computing consists of 3 layers in the hierarchy and these are as follows: 1 Infrastructure as a Service (IaaS) provides cloud infrastructure in terms of hardware like memory, processor speed etc 2 Platform as a Service (PaaS) provides cloud application platform for the developers 3 Software as a Service (SaaS) provides cloud applications which are used by the user directly without installing anything on the system The application remains on the cloud and it can be saved and edited in there only

Question 14

How does cloud computing provides on-demand functionality?

Accepted Answer

Cloud computing is a metaphor used for internet It provides on-demand access to virtualized IT resources that can be shared by others or subscribed by you It provides an easy way to provide configurable resources by taking it from a shared pool The pool consists of networks, servers, storage, applications and services

Question 15

What is the use of API’s in cloud services?

Accepted Answer

API stands for Application programming interface is very useful in cloud platforms as it allows easy implementation of it on the system It removes the need to write full fledged programs It provides the instructions to make the communication between one or more applications It also allows easy to create application with ease and link the cloud services with other systems

Question 16

What are different data types used in cloud computing?

Accepted Answer

Cloud computing is going all together for a different look as it now includes different data types like emails, contracts, images, blogs, etc The amount of data increasing day by day and cloud computing is requiring new and efficient data types to store them For example if you want to save video then you need a data type to save that Latency requirements are increasing as the demand is increasing Companies are going for lower latency for many applications

Question 17

What is the use of eucalyptus in cloud computing environment?

Accepted Answer

Eucalyptus stands for “Elastic Utility Computing Architecture for Linking Your Programs to Useful Systems” and provides an open source software infrastructure to implement clusters in cloud computing platform It is used to build private, public and hybrid clouds It can also produce your own datacenter into a private cloud and allow you to extend the functionality to many other organizations Eucalyptus provides APIs to be used with the web services to cope up with the demand of resources used in the private clouds

Question 18

What is Hypervisor in Cloud Computing and its types?

Accepted Answer

The hypervisor is a virtual machine monitor (VMM) that manages resources for virtual machines The name hypervisor is suggested as it is a supervisory tool for the virtual machines There are mainly two types of hypervisors : - Type-1: the guest Vm runs directly over the host hardware, eg Xen, Hyper-V, VmWare ESXi - Type-2: the guest Vm runs over hardware through a host OS, eg Kvm, Oracle virtualbox

Question 19

Is it cost effective to implement a private cloud rather than a public cloud and why?

Accepted Answer

It depends on the type of business that demands a cloud setup Suppose if the subscription on a public cloud for an application that is to be deployed on OS images is proving to be more costly then to buy some new datacenters and maintain them Then obviously the a private cloud has to be setup instead of a public cloud This public clouds follow utility billing methodology as electricity bill for example

Question 20

How does cloud architecture overcome the difficulties faced by traditional architecture?

Accepted Answer

Cloud architecture provide large pool of dynamic resources that can be accessed any time whenever there is a requirement, which is not being given by the traditional architecture In traditional architecture it is not possible to dynamically associate a machine with the rising demand of infrastructure and the services Cloud architecture provides scalable properties to meet the high demand of infrastructure and provide on-demand access to the user

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