Question

I was wandering about the correct way to do the following.

 a = b or c

where only one of b or c will be defined.

EDIT:
Thanks for the answers, just to clarify by not defined they are not defined at all (i.e not nil)

Answer 1

If only one or the other actually exists, you’ll need to use defined? for local variables.

a = defined? b ? b : c

With instance variables it is a little easier, assuming neither value should be falsy, since they are implicitly nil before they are defined:

a = @b || @c