// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002565/object-nullifequals

​

// @nuget: Z.ExtensionMethods

​

using System;           

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        string @this = "1";

​

        // C# Extension Method: Object - NullIfEquals

        string result1 = @this.NullIfEquals("1"); // return null;

        string result2 = @this.NullIfEquals("2"); // return "1";

​

        Console.WriteLine(result1);

        Console.WriteLine(result2);

    }

}