using System;

public class Program

{

    public static void Main()

    {

        string[][] values = new string[][]{

          new[]{"1","2","3"},

          new[]{"1.1","2.1","3.1"},

        };

        Console.WriteLine($"[{{\"y\":2019,\"p\":1,\"v\":\"{ values[0][1] }\"}}]");

​

        var v = $"[{{\"y\":2019,\"p\":1,\"v\":\"{values[0][1]}\"}}]";

        Console.WriteLine(v);

​

​

    }

}