Java Tutorial

by Dinesh Thakur Category: Java Language

A java variable can be declared using the keyword final. Then the final variable can be assigned only once.



 
by Dinesh Thakur Category: Java Language

It is better to have all numerical, strings and characters in terms of objects so to avail the facility of methods supplied with those objects. In that case, even if we want to perform any arithmetical operation, we do it with the help of methods instead of using arithmetical operators. But by this approach, performance decreases because method calls are relatively expensive.

 
by Dinesh Thakur Category: Java Language

Bytecode: The intermediate code produced by certain semi-compiled programming languages, in particular SMALLTALK and JAVA, So called because each instruction is one byte long. Source programs are com piled into bytecode, which is then executed by a bytecode INTERPRETER or VIRTUAL MACHINE that forms part of the language RUN-TIME SYSTEM. In such languages, programs may be distributed either in SOURCE CODE or in bytecode form.

 
by Dinesh Thakur Category: Java Language

When you create new projects, you should see that there is quite a lot of text that is greyed-out and contains slashes and asterisks. These are called comments and,  when you run your program, the compiler will ignore them. Comments are usually nonexecutable statements which are meant for the programmers own convenience.

A comment is usually an explanation regarding the statement. Programmers use comments to allow readers of their code to understand better the code and how it works. Comments consist of English phrases that describe the purpose of the program, the use of identifiers, and the purpose of each program step. It also makes it easier to see where an error might show up. 

 
by Dinesh Thakur Category: Java Language

A very popular WEB SERVER developed and distributed free of charge as OPEN SOURCE software by an Internet-based community of unpaid volunteers. Apache's great strengths lie in the availability of its source code and its well-defined interface for writing add-on modules: many large and profitable e-commerce sites run on modified versions of Apache. The name is a wince-making pun on the phrase 'a patchy server', bestowed because of the numerous software PATCHES released for it in its early days.

 
by Dinesh Thakur Category: Introduction to Java

Java is the object oriented, similar to C++ high-level programming language and architecture neutral developed by Sun Microsystems. Java was originally called OAK. Object Oriented meaning the capability to reuse code. Secondly, it is platform independent i.e. we don't have to develop separate applications for different platforms. It is possible to develop a single application which can run on multiple platforms like Windows, UNIX, and Macintosh systems. Java was designed for hand-held devices and set-top boxes.

 
by Dinesh Thakur Category: Introduction to Java

The different languages reflect the different styles of programming. OOP or object-oriented programming is a style of programming with a firm basis in several concepts. Those concepts revolve around objects and classes and include Polymorphism, Encapsulation, Inheritance, Abstraction and more.  Java is one of the most popular of all the object-oriented programming languages, as well as one of the easiest to learn and use.   
Any application built on objects in Java is an object-oriented application and is based on the declaration of one or more classes, with an object created from those classes and the interaction between the objects.    

 
by Dinesh Thakur Category: Introduction to Java

Defination : The objects, are the building blocks of the object oriented programming language. In some situations, a programer may use multiple objects belonging to different classes which may have some kind of relationship among themselves as they share some common features.

Let us consider an example of a program containing objects of two different classes Car and Motorcycle for maintaining car and motor cycle information respectively. Both Car and Motorcycle classes exhibit some kind of relationship as both are a kind of vehicle and share some common features like speed, engine specification etc. To represent relationship between classes, we use the concept of Inheritance.



 
by Dinesh Thakur Category: Introduction to Java

Initializing a variable is considered very helpful while making programs. We can initialize variables of primitive types at the time of their declarations. For example:

int a =10;

In Object Oriented Programming language (OOPL) like Java, the need of initialization of fields of a new object is even more common. We have already done this using two approaches.

 
by Dinesh Thakur Category: Introduction to Java

The this keyword in Java is used when a method has to refer to an object that has invoked it. It can be used inside any method to refer to the current object. This means that this is always used as a reference to the object on which the method was invoked. We can use this anywhere as reference to an object of the current class type is permitted.

 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.