Say I was to have a method that required a small number of objects to be created during each run, and the method would be called multiple times, i.e. a method to delete a given row from a database. Would it be better to create a new object each time and call the Garbage Collector (or similar) to destroy it at the end, or reinitialise the value each time?
Example:
Using new constructors each time:
private void RemoveFolder(string dir)
{
OleDbCommand cmd2 = connection.CreateCommand();
OleDbParameter parameterC = new OleDbParameter();
cmd2.Parameters.Add(parameterC);
parameterC.Value = dir;
cmd2.CommandText = "DELETE * FROM [Directories] WHERE Path = ?";
cmd2.ExecuteNonQuery();
cmd2.Dispose();
}
Using a singular global variable (initialised within the constructor):
private void RemoveFolder(string dir)
{
parameterC.Value = dir;
cmd2.CommandText = "DELETE * FROM [Directories] WHERE Path = ?";
cmd2.ExecuteNonQuery();
}
EDIT: When I say better, I mean "as-a-whole" during normal non-"mission-critical" programs, where a large increase in performance would trump a minor decrease in stability.
EDIT2
An example of calling a similar method multiple times
(Note that this is for another method of mine, AddFolder)
foreach (DirectoryInfo directory in directories)
{
parameter.Value = directory.FullName;
cmd.CommandText = "SELECT LastModified FROM Directories WHERE Path = ?";
reader = cmd.ExecuteReader();
while (reader.Read())
{
output += reader.GetString(0);
}
if (output == null)
{
Console.WriteLine("New Directory! " + directory.FullName);
AddFolder(directory);
}
output = null;
reader.Close();
}
My opinion in general,
How to measure it? You can see if your program is running to slow, or if it using to much memory..