Generic math - Factorial method

Here is a example of a generic math factorial method in C# 11. Generic math allows you to make numeric methods that makes use of the INumber generic interface, which got many static virtual methods where you can make a numeric method that supports different kinds of number types, such as decimal, int, float and double. The code below calculates the factorial of some values in an array. We have inserted a double value here that shows that Factorial of a double or any number with decimal works a bit different than ints, as the decimal part takes part here. The factorial of 0! is defined as 1 and we multiply n with n-1 as long as n > 0. Note the use of T.One and T.Zero here, defined as
static virtual members of the different number types in C#.

void Main()
{
	var someNums = new[] { 1, 2, 3, 3.141592, 5};
	var fact = someNums.Select(n =>  Factorial(n));
	fact.Dump();
	
}

T Factorial<T>(T num)
where T : INumber<T>
{
	var result = T.One;
	while (num > T.Zero){
		result *= num;
		num--;
	}
	return result;
}

Output shows the result in Linqpad 7 after having specified using .NET 7:

Trøndersk dialekttemp with C# 11 og and patterns

This article demonstrates the use of relational patterns in C# 11. First off, relational patterns allow us to test how a given value /variable compares to constants. If we want to have multiple conditions we can use and operator not shown here. I have here different conditions / intervals for temperaturs outputting the temperature and description of the weather in some local language of mine from Norway (Trøndersk / Trondheim city).

	   
    
foreach (var iteration in Enumerable.Range(0, 20)){
    var tæmpen = new Random().Next(-60, 60);
    
    var været = $"Været e i dag {tæmpen}C og på Trondheimsdialækt: {tæmpen switch 
    {
        <= -50 => "Du træng eitt nytt termometer. For kaldt!",
        <= -35 => "Småfuggel'n dætt dau fra trær'n",
        <= -30 => "Båinnspeika",
        <= -25 => "Få inn katta!",
        <= -20 => "Gnallerfrost",
        <= -10 => "Kjøle kaaalt",
        <= -5  => "Kaillvoli",
        <= 5 => "Kaillhustri",
        <= 10 => "Julivær",
        <= 15 => "Godværsle",
        <= 20 => "Kjøle varmt",
        <= 25 => "Råådeili",
        <= 30 => "Steikvarmt",
        <= 40 => "Søkke heitt",
        <= 50 => "Kokheitt",
        _ => "Du træng eitt nytt termometer. For varmt!"
    }}";
    
    System.Console.WriteLine(været);
} 
    
    

As we can see, in C# 11, we can do a lot more inside string interpolation expressions and now allow multiple lines, including relational patterns. It can be quite handy to use, when .NET 7 and C# 11 reaches mainstream usage. The text here is based upon a dialect based thermometer, available for purchase from here: https://dialekttempen.no/butikk/termometer/fylker/sor-trondelag/trondheim-munkholmen/#&gid=1&pid=1