Programming

Programming Challenge

Write a C++ program that tells whether a number is a perfect number or not.
A perfect number is a positive number which the sum of all positive divisors excluding that number.

for example 6 is perfect number since the divisor of 6 are 1,2 and 3. Sum of its divisor is
1+2+3=6

28 is also a perfect number since 1+2+4+7+14=28

Happy Coding
Have a nice day!!!

HI folks today we will introduce about Servlets
Servlets are java technology's answer to common gateway interface(CGI) programming. They are basically programs that run on a web server acting as a middle layer between a request coming from web browser or other http client and databases or applications on the HTTP server.
Their job is to
Read any data sent by the user
Look up any other information about the request that is embedded in the HTTP request.
Generate the results. (this process may require talking to a DB involving RMI )
Format the results inside a document
set the appropriate HTTP response parameters(telling the browser what type of document is being returned)
Send the document back to the client (this document may be sent in text format), binary format (images)

Servlets Architecture

Hi Folks today we will tell you about Remote Method Invocation

RMI (Remote Method Invocation) is a way that a programmer, using the Java programming language and development environment, can write object-oriented programming in which objects on different computers can interact in a distributed network. The object can include information that will change the service that is performed in the remote computer.

For example, when a user at a remote computer fills out an expense account, the Java program interacting with the user could communicate, using RMI, with a Java program in another computer that always had the latest policy about expense reporting. In reply, that program would send back an object and associated method information that would enable the remote computer program to screen the user's expense account data in a way that was consistent with the latest policy. The user and the company both would save time by catching mistakes early. Whenever the company policy changed, it would require a change to a program in only one computer.

Constructor

A class constructor is a special member function of a class that is executed whenever we create new objects of that class.

A constructor will have exact same name as the class and it does not have any return type at all, not even void. Constructors can be very useful for setting initial values for certain member variables.

Destructor

A destructor is a special member function of a class that is executed whenever an object of it's class goes out of scope or whenever the delete expression is applied to a pointer to the object of that class.

A destructor will have exact same name as the class prefixed with a tilde (~) and it can neither return a value nor can it take any parameters. Destructor can be very useful for releasing resources before coming out of the program like closing files, releasing memories etc.