Question

If I attempt to fetch a record from the db like:

@user = User.find_by_user_name("blah")

How do I check if the value was null? i.e. the record was found?

And should I use and or && as they seem to be different?

if @user and @user.age > 0
  ....
end

Answer 1

if @user
  # not nil
else
  # nil
end

should be suffice to check if the value was not nil.

And the difference between && and ‘and’ is that && has a higher precedence over ‘and’. See here