Use Same variable name in scope

Question

I need to use the same variable name to declare the connection string. But when i do this, i will have further error. I declared "SqlConnection sqlCon = new SqlConnection(strCon);" for the first variable, can i use it again? According to my teacher, i should use the same variable.

string strCon = Database.GetConStr();
    SqlConnection sqlCon = new SqlConnection(strCon);
    try
    { string strSql = "SELECT Name, ID FROM student WHERE Status = 'A' ORDER BY Name";
        SqlCommand sqlCmd = new SqlCommand(strSql, sqlCon);
        sqlCon.Open();
        SqlDataReader reader = sqlCmd.ExecuteReader();
        while (reader.Read())
        {
            ddlStaff.Items.Add(new ListItem(reader["Name"].ToString(), reader["ID"].ToString()));
        }
        reader.Close();
    }
    catch (Exception ex)
    {
        Session["Error"] = "Error in getting ... System Msg: " + ex.Message;
        Server.Transfer("Error.aspx");
    }
    finally
    {
        if (sqlCon.State == ConnectionState.Open)
            sqlCon.Close();
    }

    string strCon2 = Database.GetConStr();
    sqlCon = new SqlConnection(strCon2);
    try
    { string strSql2 = "SELECT Desc1, Desc2 FROM Parameter WHERE Paracode1 = 'Test' AND Status = 'A' ORDER BY Desc1";
        SqlCommand sqlCmd2 = new SqlCommand(strSql2, sqlCon);
        sqlCon.Open();
        SqlDataReader reader2 = sqlCmd2.ExecuteReader();
        while (reader2.Read())
        {
            ddlModule.Items.Add(new ListItem(reader2["Desc1"].ToString(), reader2["Desc22"].ToString()));
        }
        reader2.Close();
    }
    catch (Exception ex)
    {
        Session["Error"] = "Error in getting ... System Msg: " + ex.Message;
        Server.Transfer("Error.aspx");
    }
    finally
    {
        if (sqlCon.State == ConnectionState.Open)
        sqlCon.Close();
    }

Is it because i cannot use the same variable?

Answer 1

You can re-use the same variable name. The problem is that you are declaring it twice. Try removing the "SqlConnection" (the variable type) from the second instance.

Answer 2

You cannot declare the same variable name more than once within same declaration space. But you can very well use it.

try removing SqlConnection in second declaration:
    /*SqlConnection*/ sqlCon = new SqlConnection(strCon2);

If you want to declare the same name then you can define the scope for the variable name using {}

For ex:

{
    SqlConnection sqlCon = new SqlConnection(strCon);
   //use sqlCon 
}//scope ends
//sqlCon  is not available after } 
{ //new scope starts
     SqlConnection sqlCon = new SqlConnection(strCon);
}

Answer 3

try like this:- sqlConnection sqlcon= new sqlConnection(); //first connection sqlcon.connectionstring="connection string1" do some work.... //second sqlcon.connectionstring="connection string 2" ......