Which is best for perfomance?

Question

Which of the following code snippets performs fastest?

if(ClassTestBase is ClassTestChild1)

or

if(ClassTestBase.Type == EClassType.Child1)

Update:

Here is the full scenario:

public enum EInheritanceTree
{
    BaseClass,
    Child1,
    Child2,
    Child3
}

public class MyBaseClass
{
    public virtual EInheritanceTree MyClassType
    {
         get
         {
              return EInheritanceTree.BaseClass;
         }
    }
}

public vlasse MyChildClass1 : MyBaseClass
{
    public override EInheritanceTree MyClassType
    {
        get
        {
            return EInheritanceTree.Child1;
        }
    }
}

Consider a method that has to compare the class type to see what kind it is. Which is the best?

public bool IsChild1(MyBaseClass myClass)
{
     if(myClass is MyChildClass1)
          return true;

     return false;
}

or

public bool IsChild1(MyBaseClass myClass)
{
     if(myClass.MyClassType == EInheritanceTree.Child1)
          return true;

     return false;
}

Answer 1

If you're worried about performance, don't wrap all this in functions. Any code that says:

if (Obj.IsChild1() ) foo;

Should just do:

if(myClass.MyClassType == EInheritanceTree.Child1) foo;

If you're worried about the performance, any notions you may have that says to hide everything behind functions needs to be revisited. Also, why don't you just use polymorphism - that's the "right" way to make subclasses act differently.

Regardless, do some timing of your own. It's the only way to be certain which is faster.

Answer 2

Have you thought about using a profiler to test which is more performant yourself? Visual Studio comes with a profiler.

I would be more concerned about the need to have an enum that hold inheritance information about your application.