In this tutorial you will learn about the C++ Program to Find Factorial and its application with practical example.
In this tutorial, we will learn to create a C++ program that will Find Factorial of a number using C++ programming.
Prerequisites
Before starting with this tutorial we assume that you are best aware of the following C++ programming topics:
- Operators.
- Basic input/output.
- Basic c++ programming
- If-else Statement.
What is Factorial ?
Factorial of a number n is the product of all the positive integers numbers.
Example: The factorial of 6 is 120.
6! = 6* 5 * 4 * 3 * 2 *1
6! = 720.
Factorial of 0 and 1 is 1.and factorial of negative number doesn’t exist.
C++ Program to Find Factorial
In this program we will find factorial of a given number . We would first declared and initialized the required variables. Next, we would prompt user to input a number .Later we will Find Factorial.
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#include <iostream> using namespace std; int main() { int num,i; float fact = 1.0; // declaring variables cout << "Enter a positive number: "; cin >> num; // taking input number if (num < 0) // condition for negative number.. { cout << "Factorial of a negative number doesn't exist."; } else // finding factorial { for(i = 1; i <= num; ++i) { fact *= i; } cout << "Factorial of " << num << " = " << fact; } return 0; } |
Output
In the above program, we have first declared and initialized a set variables required in the program.
- num = it will hold entered number.
- fact = it will hold a factorial of a number.
- i = for iteration.
In our program, we will find factorial of a given number.
First of all we take a number as input from user and store the value in variable num.
And now we will check first that the given number is greater than 1 or not if not we show message in below.
And after that in else we will fin the factorial of a given number.
In our program above, the user is promoted to enter a positive integer.In the our program, the loop runs from 1 to num. In each iteration , fact is multiplied with i. fact=fact*i and final value of fact is the product of all numbers between 1 to num.
