Factorial calculation C# with Example
The factorial of a number (denoted with !, as for instance 9!) is the multiplication of that number with the factorial of one lower. So, for instance, 9! = 9 x 8! = 9 x 8 x 7! = 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1. So in code that becomes, using recursion: long Factorial(long x) { if (x < 1) { throw new OutOfRangeException("Factorial can only be used with positive numbers."); } if (x == 1) { return 1; } else { return x * Factorial(x - 1); } } This topic outlines some basic naming conventions used when writing in the C# language. Like all conventions, they are not enforced by the compiler, but will ensure readability between developers. For comprehensive .NET framework design guidelines, see docs.microsoft.com/dotnet/standard/design-guidelines.