Question

Is there a shorter way of writing next code in Ruby:

if defined?($servlet_context) then true
else false
end

Answer 1

The defined? operator evaluates to a string or nil:

The defined? operator returns nil if its argument (which can be an arbitrary expression) is not defined, otherwise it returns a description of that argument.

So if you just want something truthy then defined?($servlet_context) will do. However, if you absolutely must have a boolean value, then you can use a double-bang cast:

!!defined?($servlet_context)