In C# use a string builder to concatenate the query and then execute the query.
StringBuilder query = new StringBuilder();
query.Append("CREATE TABLE ");
query.Append(tableName);
query.Append(" ( ");
for (int i = 0; i < columnNames.Length; i++)
{
query.Append(columnNames[i]);
query.Append(" ");
query.Append(columnTypes[i]);
query.Append(", ");
}
if (columnNames.Length > 1) { query.Length -= 2; } //Remove trailing ", "
query.Append(")");
SqlCommand sqlQuery = new SqlCommand(query.ToString(), sqlConn);
SqlDataReader reader = sqlQuery.ExecuteReader();