FizzBuzz_Functional.cs

using System;
using System.Linq;

var output =
    Enumerable.Range(1, 50)
    .Select<int, string>((num) => num + ": " + (num % 3 == 0, num % 5 == 0)
    switch
    {
        (true, true) => "FizzBuzz",
        (true, false) => "Fizz",
        (false, true) => "Buzz",
        _ => num.ToString(),
    });


output.ToList().ForEach(x=> Console.WriteLine(x));

​FizzBuzz_Functional.output.txt

1: 1
2: 2
3: Fizz
4: 4
5: Buzz
6: Fizz
7: 7
8: 8
9: Fizz
10: Buzz
11: 11
12: Fizz
13: 13
14: 14
15: FizzBuzz
16: 16
17: 17
18: Fizz
19: 19
20: Buzz
21: Fizz
22: 22
23: 23
24: Fizz
25: Buzz
26: 26
27: Fizz
28: 28
29: 29
30: FizzBuzz
31: 31
32: 32
33: Fizz
34: 34
35: Buzz
36: Fizz
37: 37
38: 38
39: Fizz
40: Buzz
41: 41
42: Fizz
43: 43
44: 44
45: FizzBuzz
46: 46
47: 47
48: Fizz
49: 49
50: Buzz

​​.sharplab.json

{
    "version": 1,
    "target": "Run",
    "mode": "Debug"
}