This program ask to the user to enter two numbers (value of First and Second ) to interchange and display the result on the screen

Encapsulation: Encapsulation is process of wrapping of data and method in single unit.

Encapsulation provides abstraction between an object and its clients. It helps to protect an object from unwanted access by clients.

Encapsulation is a powerful feature that leads to information hiding,abstract data type and friend function.

Overloading: There are many simple definition of Overloading like:

1: In overloding function with same name having different parameters.

2: Function overloading may have different return types.

Virtual function: Virtual functions, one of advanced features of Oop is one that does not really exist but it appears real in some parts of a program.

To make a member function virtual, the keyword virtual is used in the methods while it is declared in the class definition but not in the member function definition.

Factorial: Factorial are just products,indicated by an exclamation mark. In general “n!” means the product of all the whole numbers from 1 to n; i.e n!= 1x2x3x4x……x n.

This program add up to n numbers which will be provided by user. Firstly user will enter a fix number to indicate how many numbers he wants to add and then he will enter n numbers.

Number Patterns: In C language you can print any number pattern. Here, this program teach you how print all combination of 123.

Factorial number: The factorial of any number ( let n) indicates the multiplication of series of positive integers starting from n and descending till 1.

Let’s write a program to print Largest number among three numbers in C++.

Febonacci Series : This is a type if series of numbers in which each number (Fibonacci number) is the sum of the two preceding numbers. The simplest is the series 1, 1, 2, 3, 5, 8,…… etc.