conditionally select a field depending on another field value

I want in my query to select a different field in case another one is null. in mysql i'd do it like this:

select
a
,if(b is null, c, b)
,d
from
alphabet

how can this be done in sql server?
thanks

case when b is null then c else b end

easy, wasn't it

or, in the special situation where you're testing for null and want to accept the value if it isn't, you can also say

coalesce(b,c)

Thanks