I get the following error when running FXCop:
CA1800 : Microsoft.Performance : 'obj', a variable, is cast to type 'Job' multiple times in method 'ProductsController.Details(int, int)'. Cache the result of the 'as' operator or direct cast in order to eliminate the redundant castclass instruction
Code:
object obj = repository.GetJobOrPlace(jobId);//Returns (object) place or (object) product
if (obj != null)
{
if (obj is Job)
{
Job j = (Job) obj;
Debug.WriteLine(j.Title);
}
else if (obj is Place)
{
Place p = (Place) obj;
Debug.WriteLine(p.Title);
}
}
What's wrong with this? I can only see one cast: Job j = (Job) obj.
There's only one cast but there's also a test. So you can replace the first block with:
That means the execution time test only needs to be performed once, instead of twice. It's a bit of a micro-optimisation - and in your case it would make the code a bit messier, as you'd need:
(Or declare and initialize
p
earlier, which wastes a test ifobj
is actually aJob
...)