# Simple Program for Copy Constructor Example 2 Using C++ Programming

To calculate factorial of a given number using the copy constructor.

## Definition of Factorial

In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n.

For example,

``6! = 6 x 5 x 4 x 3 x 2 x 1 = 720``

The value of 0! is 1, according to the convention for an empty product.

## Simple Program Copy Constructor Algorithm/Steps:

• STEP 1:  Start the program.
• STEP 2:  Declare the class name as Copy with data members and member functions.
• STEP 3:  The constructor Copy() with the argument to assign the value.
• STEP 4:  To call the function calculate() do the following steps.
• STEP 5:   For i=1 to var
• STEP 6:   Calculate fact*i to assign to fact.
• STEP 7:   Increment the value as 1.
• STEP 8:   Return the value fact.
• STEP 9:   Print the result.
• STEP 10: Stop the program.

## Simple Program for Copy Constructor

``````#include<iostream.h>
#include<conio.h>

class copy {
int var, fact;
public:

copy(int temp) {
var = temp;
}

double calculate() {
fact = 1;
for (int i = 1; i <= var; i++) {
fact = fact * i;
}
return fact;
}
};

void main() {
clrscr();
int n;
cout << "\n\tEnter the Number : ";
cin>>n;
copy obj(n);
copy cpy = obj;
cout << "\n\t" << n << " Factorial is:" << obj.calculate();
cout << "\n\t" << n << " Factorial is:" << cpy.calculate();
getch();
}``````

## Sample Output

``````Enter the Number: 5
Factorial is: 120
Factorial is: 120``````