public FormSponsor()
{
InitializeComponent();
SqlConnection connection1 = new SqlConnection(ConnectionStr);
SqlCommand CmdNambeStringRunner = new SqlCommand("SELECT COUNT(*) FROM [User] JOIN Rnner ON Runner.Email = [User].Email", connection: connection1);
int LengthItemsArr = 0;
using (SqlDataReader ReaderNambeTb = CmdNambeStringRunner.ExecuteReader(CommandBehavior.CloseConnection))
{
LengthItemsArr = Convert.ToInt32(ReaderNambeTb.GetValue(0).ToString());
}
string[][] ArrRinner = new string[LengthItemsArr][];
for(int i = 0; i < ArrRinner.Length; i++)
{
ArrRinner[i] = new string[4];
}
}public FormSponsor()var result = myarr_0.Select(x => x.ToCharArray()).ToArray();char[][] array = new char[myarr_0.Length][];
for (int i = 0; i < myarr_0.Length; i++)
{
for (int j = 0; j < myarr_0[i].Length; j++)
{
array[i] = new char[myarr_0[i].Length];
array[i][j] = myarr_0[i].ToCharArray(); // вот ваш вариант
}
}