// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002605/stringbuilder-extractkeyword

​

// @nuget: Z.ExtensionMethods

​

using System;

using System.Text;

public class Program

{

    public static void Main()

    {

        int endIndex;

​

        // C# Extension Method: StringBuilder - ExtractKeyword

        Console.WriteLine(new StringBuilder(" ").ExtractKeyword());

        Console.WriteLine(new StringBuilder("1.1").ExtractKeyword());

        Console.WriteLine(new StringBuilder("@1a").ExtractKeyword());

        Console.WriteLine(new StringBuilder("for foreach").ExtractKeyword().ToString());

        Console.WriteLine(new StringBuilder("zzz @for foreach").ExtractKeyword(4, out endIndex).ToString());

        Console.WriteLine(endIndex);

    }

}