is vs typeof

c# rtti
ilitirit picture ilitirit · Oct 8, 2008 · Viewed 118.8k times · Source

Which of these pieces of code is faster?

if (obj is ClassA) {}

if (obj.GetType() == typeof(ClassA)) {}

Edit: I'm aware that they don't do the same thing.

Answer

Jay Bazuzi picture Jay Bazuzi · Oct 8, 2008

Does it matter which is faster, if they don't do the same thing? Comparing the performance of statements with different meaning seems like a bad idea.

is tells you if the object implements ClassA anywhere in its type heirarchy. GetType() tells you about the most-derived type.

Not the same thing.

Related questions

How do I generate a random int number?

How do I generate a random integer in C#?

Read More
Regular expression to check if password is "8 characters including 1 uppercase letter, 1 special character, alphanumeric characters"

I want a regular expression to check that a password must be eight characters including one uppercase letter, one special character and alphanumeric characters. And here is my validation expression which is for eight characters including one uppercase letter, one …

Read More
How to make an HTTP POST web request

Canonical How can I make an HTTP request and send some data using the POST method? I can do a GET request, but I have no idea of how to make a POST request.

Read More