The following code is what I have refactored for this exercise. I get a syntax error. What is wrong with my unless and/or if statements here?
$VERBOSE = nil # We'll explain this at the end of the lesson.
require 'prime' # This is a module. We'll cover these soon!
puts "n must be an integer." unless Integer
puts "n must be greater than 0." if n <= 0
prime_array ||= 
prime = Prime.new
for num in (1..n)