Strings.dib

#!markdown

# String Constants

#!csharp

string name = "John";
string s = String.Empty;

display("-----------------");

s = "Default representation C:\\Test \" ";
display(s);
display("-----------------");

s = @"Escapes \ ignored C:\Test "" ";
display(s);
display("-----------------");

s = @"
Multiline string
Second line
Third line
";
display(s);
display("-----------------");

s = $"Interpolated |{name}|  |{1+2}|";
display(s);
display("-----------------");

s = $"Interpolated & formated |{name, 5}|  |{1+2,10}|0x{1+2,-10:X3}|";
display(s);
display("-----------------");

s = $@"
Interpolated & formated |{name, 5}|  |{1+2,10}|0x{1+2,-10:X3}|
Second line             |{" ",5}|  |{10+8,10}|0x{10+8,-10:X3}|
";
display(s);
display("-----------------");

#!markdown

# String Concatenation vs format vs interpolation

#!csharp

string name = "John";
string lastName = "Johnson";

//Concatenation
var s = "Human " + name + " " + lastName;

//Format
s = String.Format("Human {0} {1}", name, lastName);

//Interpolation
s = $"Human {name} {lastName}";

#!markdown

# String Builder

#!csharp

var stringBuilder = new StringBuilder();
stringBuilder.Append("Human ");
stringBuilder.Append(name);
stringBuilder.Append(" ");
stringBuilder.Append(lastName);
stringBuilder.ToString();

#!markdown

# Benchmarking

#!csharp

#r "nuget:BenchmarkDotNet"
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using BenchmarkDotNet.Validators;
using BenchmarkDotNet.Configs;

public class AllowNonOptimized : ManualConfig
{
    public AllowNonOptimized()
    {
        Add(JitOptimizationsValidator.DontFailOnError); // ALLOW NON-OPTIMIZED DLLS

        Add(DefaultConfig.Instance.GetLoggers().ToArray()); // manual config has no loggers by default
        Add(DefaultConfig.Instance.GetExporters().ToArray()); // manual config has no exporters by default
        Add(DefaultConfig.Instance.GetColumnProviders().ToArray()); // manual config has no columns by default
    }
}

public class StringTests
{
    [Params(2, 10, 100, 1_000, 10_000)]
    public int ConcatCount { get; set; }

    [Benchmark]
    public void AsString()
    {
        var s = "";
        for (int i = 0; i < ConcatCount; i++)
        {
            s += "0";
        }
        int len = s.Length;
    }

    [Benchmark]
    public void AsStringBuilder()
    {
        var sb = new StringBuilder();
        for (int i = 0; i < ConcatCount; i++)
        {
            sb.Append("0");
        }
        var s = sb.ToString();
        int len = s.Length;
    }
}

var r = BenchmarkRunner.Run<StringTests>(new AllowNonOptimized());

#!pwsh

cd ..
dotnet run -c Release --project ".\StringBenchmark\StringBenchmark\StringBenchmark.csproj"

#!markdown

|          Method | ConcatCount |            Mean |         Error |        StdDev |
|---------------- |------------ |----------------:|--------------:|--------------:|
|        AsString |           2 |        13.65 ns |      0.303 ns |      0.618 ns |
| AsStringBuilder |           2 |        20.98 ns |      0.406 ns |      0.379 ns |
|        AsString |          10 |        94.59 ns |      1.149 ns |      1.075 ns |
| AsStringBuilder |          10 |        42.36 ns |      0.283 ns |      0.265 ns |
|        AsString |         100 |     1,467.72 ns |     20.938 ns |     19.585 ns |
| AsStringBuilder |         100 |       412.63 ns |      3.603 ns |      2.813 ns |
|        AsString |        1000 |    66,141.90 ns |    698.616 ns |    583.376 ns |
| AsStringBuilder |        1000 |     3,081.56 ns |     24.370 ns |     22.795 ns |
|        AsString |       10000 | 5,182,357.86 ns | 97,435.630 ns | 91,141.349 ns |
| AsStringBuilder |       10000 |    29,345.32 ns |    178.283 ns |    158.043 ns |