Skip to main content

Privado.com - A Private Search Engine

https://www.privado.com/ Your searches should be private. We make sure they really are.  Private Search in Action  We don’t track you  We don’t store your searches in any identifiable way  We don’t store your IP address in our services Your privacy is important.  There are no traces of your activities and personal identity in our servers.  You can learn more about privacy in our blog  We don't like cookies!   https://www.privado.com/

Java J2EE Interview Questions and Answers - Part 1

  1. What is the difference between procedural and object-oriented programs?- a) In procedural program, programming logic follows certain procedures and the instructions are executed one after another. In OOP program, unit of program is object, which is nothing but combination of data and code. b) In procedural program, data is exposed to the whole program whereas in OOPs program, it is accessible within the object and which in turn assures the security of the code.
  2. What are Encapsulation, Inheritance and Polymorphism?- Encapsulation is the mechanism that binds together code and data it manipulates and keeps both safe from outside interference and misuse. Inheritance is the process by which one object acquires the properties of another object. Polymorphism is the feature that allows one interface to be used for general class actions.
  3. What is the difference between Assignment and Initialization?- Assignment can be done as many times as desired whereas initialization can be done only once.
  4. What is OOPs?- Object oriented programming organizes a program around its data, i. e. , objects and a set of well defined interfaces to that data. An object-oriented program can be characterized as data controlling access to code.
  5. What are Class, Constructor and Primitive data types?- Class is a template for multiple objects with similar features and it is a blue print for objects. It defines a type of object according to the data the object can hold and the operations the object can perform. Constructor is a special kind of method that determines how an object is initialized when created. Primitive data types are 8 types and they are: byte, short, int, long, float, double, boolean, char.
  6. What is an Object and how do you allocate memory to it?- Object is an instance of a class and it is a software unit that combines a structured set of data with a set of operations for inspecting and manipulating that data. When an object is created using new operator, memory is allocated to it.
  7. What is the difference between constructor and method?- Constructor will be automatically invoked when an object is created whereas method has to be called explicitly.
  8. What are methods and how are they defined?- Methods are functions that operate on instances of classes in which they are defined. Objects can communicate with each other using methods and can call methods in other classes. Method definition has four parts. They are name of the method, type of object or primitive type the method returns, a list of parameters and the body of the method. A method’s signature is a combination of the first three parts mentioned above.
  9. What is the use of bin and lib in JDK?- Bin contains all tools such as javac, appletviewer, awt tool, etc., whereas lib contains API and all packages.
  10. What is casting?- Casting is used to convert the value of one type to another.
  11. How many ways can an argument be passed to a subroutine and explain them?- An argument can be passed in two ways. They are passing by value and passing by reference. Passing by value: This method copies the value of an argument into the formal parameter of the subroutine. Passing by reference: In this method, a reference to an argument (not the value of the argument) is passed to the parameter.
  12. What is the difference between an argument and a parameter?- While defining method, variables passed in the method are called parameters. While using those methods, values passed to those variables are called arguments.
  13. What are different types of access modifiers?- public: Anything declared as public can be accessed from anywhere. private: Anything declared as private can’t be seen outside of its class. protected: Anything declared as protected can be accessed by classes in the same package and subclasses in the other packages. default modifier : Can be accessed only to classes in the same package.
  14. What is final, finalize() and finally?- final : final keyword can be used for class, method and variables. A final class cannot be sub classed and it prevents other programmers from sub classing a secure class to invoke insecure methods. A final method can’t be overridden. A final variable can’t change from its initialized value. finalize() : finalize() method is used just before an object is destroyed and can be called just prior to garbage collection. finally : finally, a key word used in exception handling, creates a block of code that will be executed after a try/catch block has completed and before the code following the try/catch block. The finally block will execute whether or not an exception is thrown. For example, if a method opens a file upon exit, then you will not want the code that closes the file to be bypassed by the exception-handling mechanism. This finally keyword is designed to address this contingency.
  15. What is UNICODE?- Unicode is used for internal representation of characters and strings and it uses 16 bits to represent each other.

Comments

Popular Posts

DOT NET Interview Questions with Answers

When not to use Design Patterns? Do not use design patterns in any of the following situations. • When the software being designed would not change with time. • When the requirements of the source code of the application are unique. If any of the above applies in the current software design, there is no need to apply design patterns in the current design and increase unnecessary complexity in the design. When to use Design Patterns? Design Patterns are particularly useful in one of the following scenarios. • When the software application would change in due course of time. • When the application contains source code that involves object creation and event notification. Benefits of Design Patterns: The following are some of the major advantages of using Design Patterns in software development. • Flexibility • Adaptability to change • Reusability What are Design Patterns? A Design Pattern essentially consists of a problem in a software design and a solutio

Probationary/ Specialist Officers in Indian Bank

Probationary/ Specialist Officers Location :  Across India Eligibility: BE/ B.Tech (Che/ Electrical/ Mech/ Prdn/ Textile/ ETE/ ECE/ CS/ IT)/ MCA/ MBA www.freshersworld.com Details:     Indian Bank (A Govt of India Undertaking) Recruitment of Probationary Officers/ Specialist Officers (Industrial Development Officers/ Computer Officers) Indian Bank, a leading Public Sector Bank, with headquarters in Chennai having geographical presence all over India and abroad invites online applications from Indian Citizens for the following posts. Post Code Post Scale Total Vacancy Age as on 01.07.09 Min Max 1 Probationary Officers I 118 21 30 Specialist Officers         Industrial Development Officers in the following Engineering disciplines         2 Chemical I 02 21 30 3 Electrical I 02 21 30 4 Electronics I 02 21 30 5 Leather Technology I 02 21 30 6 Mechanical I 02 21 30 7 Production/ Metallurgy I 02

DesignEvo - A free and easy online logo designer

DesignEvo is  easy-to-use online logo design tool with millions of icons, 100+ stylish  fonts, 3,000+ practical logo templates and handy editing tools. It can help  people easily create appealing and effective logos for their brands,  websites, blogs, social media channels, etc.  It is really awesome and intuitive interface. Easy to design and customize. A person can easily design by selecting a pre-defined logo design and modify it on the fly. Hardly you need 1 minute to design your new logo with minor modifications. Its really awesome site. I suggest you to try it out.   You can discover more about DesignEvo here: https://www.designevo.com Learn more about Designevo  @ YouTube designevo, free logo design, logo maker, create a logo, easy logo maker, design logo free, free logo, logo designs, logo images

Free Softwares 09 July 09

JDownloader JDownloader, open source and platform independent, can help download files from file hosters like Rapidshare.com, Megaupload.com and others. JDownloader can be used by both kinds of users - those who have a premium account and those who don't pay. Features: Support for many file hosting sites, decrypt plug-ins for many services. e.g. sj.org, UCMS, WordPress, skips the limits of Filehosting websites, downloads in multiple paralell streams, download with multiple connections, captcha recognition, automatical file extraction, Can download Youtube, Vimeo, clipfish video, and Mp3 files; 24-hour support, integrates with Firefox, no installation needed, and more. The 15.6 MB JDownloader, v.0.6.193, cross-platform - works on Windows, Linux and Mac OS X, can be downloaded at http://jdownloader.en.softonic.com/download Runs on Java 1.5 or higher. jGnash jGnash is a free personal finance manager with many features available in commercial versions. Main Features

Mobile Number Portability in India by Sept 20

Department of Telecom has issued ( .pdf ) a notification stating that long awaited number portability will finally be available by September 20. The main object of number portability is to be able to retain the same number even after switching between different mobile service providers.   Mobile Number Portability gives a mobile subscriber the leverage of retaining his/her mobile phone number even after switching between networks. As per Department of Telecom - Mobile Number Portability is to be implemented in Delhi, Mumbai, Maharashtra and Gujarat Service areas of Zone I and Zone 2 includes Kolkata, Tamil Nadu, Chennai, Andhra and Karnataka of within six months of award of license by September 20, 2009, and in the rest of the country by March 20, 2010. Syniverse Technologies have been licensed for MNP operations in Zone I while MNP Interconnection got licensed for MNP operations in Zone 2.   TRAI will decide all kinds of mobile number portability tariffs like the transaction

Contact Form

Name

Email *

Message *