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. Procedural programming decomposes a program into various different functional units, each of which can gather and manipulate data as needed.

 
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

'this' pointer is used when a method has to refer to an object that has invoked it. 'this' pointer 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. Since, it is illegal in Java to declare two local variables with the same name inside the same or enclosing scopes; we can have local variables, which include formal parameters to methods, which may overlap with the names of the class instance variables. However, when a local variable has the same name as an instance variable, the local variable hides the instance variable.

 
by Dinesh Thakur Category: Introduction to Java

In this Example we Reading amount, Year and interest in the class Scanner becomes analogous to reading string. In this example, the three numbers are read from the console, and then perform Simple Interest,Compound Interest operations and results printed on the screen in formatted output.

 
by Dinesh Thakur Category: Introduction to Java

The RMI architecture, shown in Figure, describes how remote objects behave and how parameters are passed between remote methods. Remote method invocation allows the program to define separately the behaviour and the code that implements the behaviour and allows running them on separate JVMs. This principle facilitates the clients to focus on the definition of a service while the servers can focus on providing the service.

 
by Dinesh Thakur Category: Introduction to Java

Enumeration (enum) was not originally available in Java though it was available in other language like C and C++ but eventually Java realized and added to version 5 of Java were the safe type enumerations (Type Safe Enums), which allows you to create enums in Java, just as they exist in other technologies. It is defined by the reserved word enum, and each item in the enumeration is represented by an object of the same type as the Enum. The definition of an enumeration is no more than the definition of a special kind of class. If they were in another package, they should be imported like any other normal classes.

 
by Dinesh Thakur Category: Introduction to Java

Polymorphism is a very powerful concept that allows you to design amazingly flexible applications. The word 'Polymorphism: is derived form two Greek words 'poly' which means many and 'morphos' which means forms. So, polymorphism means the ability to take many forms.

 
by Dinesh Thakur Category: Introduction to Java

Modifiers are keywords used to define the scope and behaviour of classes, methods and variables in Java. Access modifiers specified who can access them. Java has a wide variety of modifiers that can be categorized as shown below:

 

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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.