What is fastest: (int), Convert.ToInt32(x) or Int32.Parse(x)?

Question

Which of the following code is fastest/best practice for converting some object x?

int myInt = (int)x;

or

int myInt = Convert.T         


        

Answer 1

foreach(DataRow row in someTable.Rows)
{
    myInt = (int)row["some int value"];
    myInt2 = Int.Parse(row["some int value"]);
    myInt2 = Convert.ToInt32(row["some int value"]);
}

For this example, if the value coming from the table is indeed an int value, or comparable database value, then using the

myInt = (int)row["some int value"];

would be the most efficient, and hence the 'fastest' becuase the

row["some int value"];

will be a value-type int instance boxed inside an reference-type object instance, so using the explicit type cast will be the quickest becuase as other people said it is an operation not a function call, thereby reducing the cpu operations required. A call to a converion or parse method would require extra cpu operations and hence not be as 'fast'.