Calculating Factorials in C#: A Simple and Efficient Iterative Approach

Learn how to calculate factorials in C# using an iterative approach. This tutorial provides a clear code example, explains the factorial calculation process, and demonstrates error handling for invalid inputs, providing a practical and efficient solution.

Calculating Factorials in C#

Understanding Factorials

The factorial of a non-negative integer n (denoted as n!) is the product of all positive integers less than or equal to n. For example, 5! (5 factorial) is 5 * 4 * 3 * 2 * 1 = 120. Factorials are commonly used in mathematics, particularly in combinatorics (calculations involving combinations and permutations).

C# Factorial Program using a `for` loop

This C# program calculates the factorial of a number entered by the user using a `for` loop. It iteratively multiplies numbers from 1 up to the input number to compute the factorial. Error handling (e.g., checking for negative input) is not included in this simple example.

using System;

public class FactorialExample {
    public static void Main(string[] args) {
        Console.Write("Enter a non-negative integer: ");
        int number = int.Parse(Console.ReadLine());
        long factorial = CalculateFactorial(number);
        Console.WriteLine($"Factorial of {number}: {factorial}");
    }

    public static long CalculateFactorial(int n) {
        if (n < 0) {
            throw new ArgumentException("Input must be non-negative.");
        }
        long factorial = 1;
        for (int i = 1; i <= n; i++) {
            factorial *= i;
        }
        return factorial;
    }
}

Conclusion

This program demonstrates a straightforward method for calculating factorials in C#. The `for` loop efficiently computes the factorial, and the `CalculateFactorial` function handles potential errors due to negative inputs, making the program more robust.