Computer Engineering & Management Notes

         In some programming languages, function overloading or method overloading is the ability to create multiple methods of the same name with different implementations. Calls to an overloaded function will run a specific implementation of that function appropriate to the context of the call, allowing one function call to perform different tasks depending on context.

For example, doTask() and doTask(object O) are overloaded methods. To call the latter, an object must be passed as a parameter, whereas the former does not require a parameter, and is called with an empty parameter field. A common error would be to assign a default value to the object in the second method, which would result in an ambiguous call error, as the compiler wouldn't know which of the two methods to use.

Another appropriate example would be a Print(object O) method. In this case one might like the method to be different when printing, for example, text or pictures. The two different methods may be overloaded as Print(text_object T); Print(image_object P). If we write the overloaded print methods for all objects our program will "print", we never have to worry about the type of the object, and the correct function call again, the call is always: Print(something).

       In class-based object-oriented programming, a constructor is a special type of subroutine called to create an object. It prepares the new object for use, often accepting arguments that the constructor uses to set required member variables.

A constructor resembles an instance method, but it differs from a method in that it has no explicit return type, it is not implicitly inherited and it usually has different rules for scope modifiers. Constructors often have the same name as the declaring class. They have the task of initializing the object's data members and of establishing the invariant of the class, failing if the invariant is invalid. A properly written constructor leaves the resulting object in a valid state. Immutable objects must be initialized in a constructor.

Programmers also use the term constructor to denote one of the tags that wraps data in an algebraic data type.

Most languages allow overloading the constructor in that there can be more than one constructor for a class, with differing parameters. Some languages take consideration of some special types of constructors. Constructors, which concretely use a single class to create objects and return a new instance of the class, are abstracted by factories, which also create objects but can do so in various ways, using multiple classes or different allocation schemes such as an object pool.

      An application server is a program in a computer in a distributed network that provides the business logic for an application program. A proxyserver is software that acts as an intermediary between an endpoint device, such as a computer, and another server from which a user or client is requesting a service.

         The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, and hypermedia information systems.HTTP is the foundation of data communication for the World Wide Web. Hypertext is structured text that uses logical links (hyperlinks) between nodes containing text.

        A web page or webpage is a document commonly written in HyperText Markup Language (HTML) that is accessible through the Internet or other network using an Internet browser. A web page is accessed by entering a URL address and may contain text, graphics, and hyperlinksto other web pages and files. The page you are reading now is an example of a web page.

• Electronic Mail(email)
• Entertainment
• Online Banking(e-banking)
• Online Discussion(Chatting)
• Online Shopping(e-business)
• Software Development
• Video Conference
• Customer Support Service