---
lang: ja-jp
breaks: true
---
# C# `String Interpolation` `文字列補間` の速度調査 2021-10-20

軽量な文字列処理を１億回実行する速度調査

string pid = "XXXX0001";
string message = "String interpolation in C#";
string discription = "Test the processing speed.";

var maxCount = 100000000;

Action<string> action = (string str) => {
    //Console.WriteLine(str);
};

{
    Stopwatch sw = Stopwatch.StartNew();
    string str = null;
    for (int i = 0; i < maxCount; i++)
    {
        str = "[" + pid + "]" + message + " " + discription;
    }
    action(str);

    sw.Stop();
    Console.WriteLine($"string operator      {sw.Elapsed.ToString()}");
}

{
    Stopwatch sw = Stopwatch.StartNew();
    string str = null;
    for (int i = 0; i < maxCount; i++)
    {
        str = string.Format("[{0}]{1} {2}", pid, message, discription);
    }
    action(str);

    sw.Stop();
    Console.WriteLine($"string Format        {sw.Elapsed.ToString()}");
}

{
    Stopwatch sw = Stopwatch.StartNew();
    sw.Start();
    string str = null;
    for (int i = 0; i < maxCount; i++)
    {
        str = $"[{pid}]{message} {discription}";
    }
    action(str);

    sw.Stop();
    Console.WriteLine($"string interpolation {sw.Elapsed.ToString()}");
}

{
    Stopwatch sw = Stopwatch.StartNew();
    sw.Start();
    var sbr = new StringBuilder();
    string str = null;
    for (int i = 0; i < maxCount; i++)
    {
        sbr.Clear();
        str = sbr.Append("[").Append(pid).Append("]").Append(message).Append(" ").Append(discription).ToString();
    }
    action(str);

    sw.Stop();
    Console.WriteLine($"StringBuilder        {sw.Elapsed.ToString()}");
}

{
    Stopwatch sw = Stopwatch.StartNew();
    sw.Start();
    string str = null;
    for (int i = 0; i < maxCount; i++)
    {
        var sbr = new StringBuilder();
        str = sbr.Append("[").Append(pid).Append("]").Append(message).Append(" ").Append(discription).ToString();
    }
    action(str);

    sw.Stop();
    Console.WriteLine($"StringBuilder new()  {sw.Elapsed.ToString()}");
}

## `.NET Framework 4.8`

string operator      00:00:08.5226781
string Format        00:00:11.3753951
string interpolation 00:00:08.3150392
StringBuilder        00:00:04.3054870
StringBuilder new()  00:00:13.4636749

## `.NET Core 6.0`

string operator      00:00:05.9941010
string Format        00:00:09.4145695
string interpolation 00:00:05.3217175
StringBuilder        00:00:04.0855460
StringBuilder new()  00:00:11.5702057

###### tags: `C#` `String Interpolation` `文字列補間` `速度`