Remove Whitespaces C#

RemoveWhitespacesSpeedTest.cs

| Method                       | Mean       | Error    | StdDev   | Ratio | RatioSD | Gen0   | Allocated | Alloc Ratio |
|----------------------------- |-----------:|---------:|---------:|------:|--------:|-------:|----------:|------------:|
| StringReplace                |   355.6 ns |  1.81 ns |  1.69 ns |  1.00 |    0.01 | 0.0381 |     480 B |        1.00 |
| CharIsWhitespace             |   972.5 ns | 18.16 ns | 32.27 ns |  2.73 |    0.09 | 0.2804 |    3528 B |        7.35 |
| CharIsWhitespace_ToCharArray | 1,074.9 ns |  6.66 ns |  5.20 ns |  3.02 |    0.02 | 0.2918 |    3672 B |        7.65 |
| GeneratedRegex               | 1,087.5 ns |  2.60 ns |  2.31 ns |  3.06 |    0.02 | 0.0381 |     480 B |        1.00 |

// .Net 9 / C# 13  

// * Legends *
  Mean        : Arithmetic mean of all measurements
  Error       : Half of 99.9% confidence interval
  StdDev      : Standard deviation of all measurements
  Ratio       : Mean of the ratio distribution ([Current]/[Baseline])
  RatioSD     : Standard deviation of the ratio distribution ([Current]/[Baseline])
  Gen0        : GC Generation 0 collects per 1000 operations
  Allocated   : Allocated memory per single operation (managed only, inclusive, 1KB = 1024B)
  Alloc Ratio : Allocated memory ratio distribution ([Current]/[Baseline])
  1 ns        : 1 Nanosecond (0.000000001 sec)



public partial class BenchmarkTest
{
    [Benchmark(Baseline = true)]
    public string StringReplace()
    {
        string result = "";
        foreach (string value in Values)
        {
            result = StringReplace(value);
        }

        return result;
    }

    [Benchmark]
    public string CharIsWhitespace()
    {
        string result = "";
        foreach (string value in Values)
        {
            result = CharIsWhiteSpace(value);
        }

        return result;
    }

    [Benchmark]
    public string CharIsWhitespace_ToCharArray()
    {
        string result = "";
        foreach (string value in Values)
        {
            result = CharIsWhiteSpace_WithToCharArray(value);
        }

        return result;
    }

    [GeneratedRegex(@"\s+")]
    private static partial Regex MyRegex();

    [Benchmark]
    public string GeneratedRegex()
    {
        string result = "";
        foreach (string value in Values)
        {
            result = RegexReplace(value);
        }

        return result;
    }

    private static string StringReplace(string                    input) => input.Replace(" ", "");
    private static string CharIsWhiteSpace(string                 input) => new(input.Where(c => char.IsWhiteSpace(c) is false).ToArray());
    private static string CharIsWhiteSpace_WithToCharArray(string input) => new(input.ToCharArray().Where(c => char.IsWhiteSpace(c) is false).ToArray());
    private static string RegexReplace(string                     input) => MyRegex().Replace(input, "");

    private static readonly List<string> Values =
    [
        "1234567890",
        "0987654321",
        "1112223334",
        "5555555555",

        // 10-digit numbers (a few spaces)
        "12345 67890",
        "12 345 67890",
        "12 345 678 90",
        "123 4567 890",
        "1234  567  890",

        // 10-digit numbers (many/leading/trailing spaces)
        " 1234567890",
        "1234567890 ",
        "  1234567890  ",
        "1 2 3 4 5 6 7 8 9 0",
        "12   3456  7890",

        // Letter-only usernames
        "alice",
        "bob",
        "charlie",
        "david",
        "eve",
        "frank",
    ];
}