private static string digits = "0123456789";
public static void Main()
Console.WriteLine(GenerateCodeOld());
Console.WriteLine(GenerateCodeNew());
private static string GenerateCodeOld() {
Random rnd = new Random();
for (int i = 0; i < 6; i++)
code += digits[rnd.Next(0, 10)];
private static string GenerateCodeNew() {
string code = new Random().Next(0, 1000000).ToString().PadLeft(6, '0');